Agilent E4406A GSM Measurement Guide

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GSM Measurement Guide

Agilent Technologies E4406A VSA Series

Transmitter Tester

Manufacturing Part Number: E4406-90131

Printed in USA

July 2000

The information contained in this document is subject to change without notice.

Agilent Technologiesmakesnowarrantyofanykindwithregard to this material, including but not limited to, the implied warranties of merchantability and ﬁtness for a particular purpose. Agilent Technologies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Contents

1. Understanding GSM

What Is GSM?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Mobile Stations and Base Transceiver Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Uplink and Downlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

What Is an ARFCN? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

What are Timeslots? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

What Does the Agilent Technologies E4406A VSA Series Transmitter Tester Do?. . . . . . . . 11

Other Sources of Measurement Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Instrument Updates at www.agilent.com/ﬁnd/vsa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2. Setting Up the GSM Mode

Accessing the Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

How to Make a Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Changing the Mode Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Demod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Changing the Frequency Channel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

GSM Measurement Key Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Installing Optional

Measurement Personalities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Available Personality Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

License Key Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Installing a License Key Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Using the Uninstall Key. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

3. Making GSM Measurements

GSM Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Preparing for Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Initial Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

How to Make a Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Measurement Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Averaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Trig Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Burst Sync . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Making the Transmit Power Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Measurement Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Making the Power vs. Time Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Measurement Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Contents

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Power vs. Time Custom Masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Changing the View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Changing the Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Making the Phase and Frequency Error Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Changing the View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Changing the Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

Making the Output RF Spectrum Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Changing the View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Making the Spectrum (Frequency Domain) Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

Changing the View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Windows Available for Spectrum Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Using the Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Band Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Making the Waveform (Time Domain) Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Changing the View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Windows Available for Waveform Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Using the Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Band Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

Making the Tx Band Spur Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94

Contents

Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Changing the View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96

Contents

1 Understanding GSM

Understanding GSM

What Is GSM?

The Global System for Mobile communication (GSM) digital communications standard deﬁnes a voice and data over-air interface between a mobile radio and the system infrastructure. This standard was designed as the basis for a radio communications system. A base station control center (BSC) is linked to multiple base transceiver station (BTS) sites which provide the required coverage.

GSM 900, GSM 450, GSM 480, GSM 850, DCS 1800, and PCS 1900 are GSM-deﬁned frequency bands. The term GSM 900 is used for any GSM system operating in the 900 MHz band, which includes P-GSM, E-GSM, and R-GSM. Primary (or standard) GSM 900 band (P-GSM) is the original GSM band. Extended GSM 900 band (E-GSM) includes all the P-GSM band plus an additional 50 channels. Railway GSM 900 band (R-GSM) includes all the E-GSM band plus additional channels.

DCS 1800 is an adaptation of GSM 900, created to allow for smaller cell sizes for higher system capacity. PCS 1900 is intended to be identical to DCS 1800 except for frequency allocation and power levels. The term GSM 1800 is sometimes used for DCS 1800, and the term GSM 1900 is sometimesusedforPCS1900.Forspeciﬁcsonthebands,refertoTable

1-1.

The GSM digital communications standard employs an 8:1 Time Division Multiple Access (TDMA) allowing eight channels to use one carrier frequency simultaneously. The 270.833 kbits/second raw bit rate is modulated on the RF carrier using Gaussian Minimum Shift Keying (GMSK).

The standard includes multiple trafﬁc channels (TCH), a control channel (CCH), and a broadcast control channel (BCCH). The GSM speciﬁcation deﬁnes a channel spacing of 200 kHz.

8 Chapter1

Table 1-1 GSM Band Data

Understanding GSM

What Is GSM?

P-GSM

(GSM 900)

Uplink (MS Transmit)

Downlink (BTS Transmit)

Range (ARFCN)

TX/RX Spacing (Freq.)

TX/RX Spacing (Time)

Modulation Data Rate

GMSK (kbits/s): 8PSK (kbits/s):

Frame Period 4.615 ms 4.615 ms 4.615 ms 4.615 ms 4.615 ms Timeslot Period 576.9 µs 576.9 µs 576.9µs 576.9 µs 576.9 µs Bit Period 3.692 µs 3.692 µs 3.692 µs 3.692 µs 3.692 µs Modulation 0.3 GMSK

890 to 915 MHz

935 to 960 MHz

1 to 124 0 to 124

45 MHz 45 MHz 45 MHz 95 MHz 80 MHz

3 timeslots 3 timeslots 3 timeslots 3 timeslots 3 timeslots

270.833

812.499

3π/8 8PSK

E-GSM

(GSM 900)

880 to 915 MHz

925 to 960 MHz

and 975 to 1023

270.833

812.499

0.3 GMSK 3π/8 8PSK

R-GSM

(GSM 900)

876 to 915 MHz

921 to 960 MHz

1 to 124 and 955 to1023

270.833

812.499

0.3 GMSK 3π/8 8PSK

DCS 1800

(GSM 1800)

1710 to 1785 MHz

1805 to 1880 MHz

512 to 885 512 to 810 259 to 293 306 to 340 128 to 251

270.833

812.499

0.3 GMSK 3π/8 8PSK

PCS 1900

(GSM 1900)

1850to1910 MHz

1930to1990 MHz

270.833

812.499

0.3 GMSK 3π/8 8PSK

GSM 450 GSM 480 GSM 850

450.4 to

457.6 MHz

460.4 to

467.6 MHz

45 MHz 45 MHz 45 MHz

3 timeslots 3 timeslots 3 timeslots

270.833

812.499

4.615 ms 4.615 ms 4.615 ms

576.9 µs 576.9 µs 576.9 µs

3.692 µs 3.692 µs 3.692 µs

0.3 GMSK 3π/8 8PSK

478.8 to 486 MHz

488.8 to 496 MHz

270.833

812.499

0.3 GMSK 3π/8 8PSK

824 to 849 MHz

869 to 894 MHz

270.833

812.499

0.3 GMSK 3π/8 8PSK

Channel Spacing 200 kHz 200 kHz 200 kHz 200 kHz 200 kHz TDMA Mux 88888 MS Max Power 20 W(8 Wis

max in use)

MS Min Power 13 dBm 5 dBm 0 dBm 0 dBm 0 dBm 5 dBm 5 dBm 5 dBm MS Power

Control Steps Voice Coder

Bit Rate

0 to 15 2 to 19 2 to 19 0 to 15

13 kbits/s 13 kbits/s,

20 W 20 W 20 W 20 W

0 to 15

29,30,31

13 kbits/s 13 kbits/s 13 kbits/s

5.6 kbits/s

30, 31,

200 kHz 200 kHz 200 kHz 888 20 W 20 W 20 W

2 to 19 2 to 19 2 to 19

13 kbits/s 13 kbits/s 13 kbits/s

The GSM framing structure is based on a hierarchical system consisting of timeslots, TDMA frames, multiframes, superframes, and hyperframes. One timeslot is 156.25 (157) bit periods including tail, training sequence, encryption, guard time, and data bits. Eight of these timeslots make up one TDMA frame. Either 26 or 51 TDMA frames make up one multiframe. Frames 13 and 26 in the 26 frame multiframe are dedicated to control channel signaling.

Chapter 1 9

Understanding GSM

What Is GSM?

Mobile Stations and Base Transceiver Stations

The cellular system includes the following:

• base transceiver stations, referred to as BTS (frequency ranges dependent on the standard; refer to Table 1-1)

• mobile stations, referred to as MS (frequency ranges dependent on the standard; refer to Table 1-1)

Uplink and Downlink

Uplink is deﬁned as the path from the mobile station to the base transceiver station. Downlink is the path from the base transceiver station to the mobile station.

What Is an ARFCN?

An ARFCN is the Absolute Radio Frequency Channel Number used in the GSM system. Each RF channel is shared by up to eight mobile stations using Time Division Multiple Access (TDMA). The ARFCN is aninteger(inarangedependentonthechosenstandard,refertoTable

1-1) which designates the carrier frequency.

What are Timeslots?

GSM utilizes Time Division Multiple Access (TDMA) with eight time slots per RF channel which allows eight users to use a single carrier frequency simultaneously. Users avoid one another by transmitting in series. The eight users can transmit once every 4.62 ms for 1 timeslot which is 577 µs long. The eight user timeslots are numbered from 0 to 7.

Typically, each 577 µs timeslot has a length of 156.25 bit periods, which consists of 148 data bits and 8.25 guard bits. The 4.62 ms required to cycle through eight timeslots is called a frame. In a TDMA system, the shape of each transmitted burst must be controlled carefully to avoid over-lapping bursts in time.

10 Chapter1

Understanding GSM

What Does the Agilent Technologies E4406A VSA Series Transmitter Tester Do?

The E4406A VSA Series Transmitter Tester makes measurements that conform to the GSM 5.04, 5.05, 11.10, 11.21, and ANSI J-STD-007 speciﬁcations.

These documents deﬁne complex, multi-part measurements used to maintain an interference-free environment. For example, the documents include measuring the power of a carrier. The E4406A automatically makes these measurements using the measurement methods and limits deﬁned in the standards. The detailed results displayed by the measurements allow you to analyze GSM system performance. You may alter the measurement parameters for specialized analysis.

This instrument was primarily developed for making measurements on digital transmitter carriers. These measurements can help determine if a GSM transmitter is working correctly. The E4406A is capable of measuring the continuous carrier of a base station transmitter.

For infrastructure test, the instrument will test base station transmitters in a non-interfering manner by means of a coupler or power splitter.

This instrument makes the following measurements:

• Transmit Power

• Power versus Time

• Phase and Frequency Error

• Output RF Spectrum

• Spectrum (Frequency Domain)

• Waveform (Time Domain)

• Tx Band Spur

Chapter 1 11

Understanding GSM

Other Sources of Measurement Information

Additional measurement application information is available through your local Agilent Technologies sales and service ofﬁce. The following application notes treat digital communications measurements in much greater detail than discussed in this measurement guide.

• Application Note 1298 Digital Modulation in Communications Systems - An Introduction part number 5965-7160E

• Application Note 1312 Understanding GSM Transmitter Measurements for Base Transceiver Stations and Mobile Stations part number 5966-2833E

Instrument Updates at www.agilent.com/ﬁnd/vsa

This web location can be used to access the latest information about the transmitter tester.

12 Chapter1

2 Setting Up the GSM Mode

Setting Up the GSM Mode

Accessing the Mode

At initial power up, the transmitter tester will come up in the Basic mode, with the Spectrum (Frequency Domain) measurement selected and the Measure menu displayed.

To access the GSM measurement personality, press the select the

GSM key.

MODE key and

If you want to set the mode to a known factory default state, press

Preset. This will preset the mode setup and all of the measurements to

the factory default parameters.

NOTE Note that pressing the Preset key does not switch instrument modes.

You may want to install a new personality, reinstall a personality that you have previously uninstalled, or uninstall a personality option. Instructions can be found in “Installing Optional Measurement Personalities” in this section.

14 Chapter2

Setting Up the GSM Mode

How to Make a Measurement

Follow the three-step process shown in the table below:

Step Primary Key Setup Keys Related Keys

1. Select & setup a mode

2. Select & setup a measurement

3. Select & setup view

Mode Mode Setup, Input,

Frequency Channel

Measure Meas Setup Meas Control,

View/Trace Span X Scale,

Amplitude Y Scale Next Window, Zoom

, Display,

System

Restart File

, Save,

Print, Print Setup, Marker, Search

Chapter 2 15

Setting Up the GSM Mode

Changing the Mode Setup

Numerous settings can be changed at the mode level by pressing the

Mode Setup key. This will access a menu with the selections listed below.

These settings affect all the measurements in the GSM mode.

Radio

The Radio key accesses a menu to select:

Band - Select the GSM band (P-GSM, E-GSM, R-GSM, GSM 450,

• GSM 480, GSM 850, DCS 1800, or PCS 1900). Refer to the table in the previous section for GSM band data.

•

Device - Select the device to test BTS (Base Transceiver Station) or

MS (Mobile Station).

• BTS Type - Select the type of BTS (Base Transceiver Station) to be tested (Normal, Micro, or Pico).

• Freq Hopping - Turn frequency hopping on or off. If frequency hopping is turned on, the instrument will ignore the bursts when the frequency is hopped off the selected channel frequency. Thus only valid data is included in the results. Only the Power vs. Time, and the Phase and Frequency Error measurements can be made on hopping GSM signals.

•

Carrier - Select the type of carrier to measure (Burst or Continuous).

Radio Default Settings

Band E-GSM Device BTS BTS Type Normal Freq Hopping Off Carrier Burst

16 Chapter2

Setting Up the GSM Mode

Changing the Mode Setup

Input

The Input key accesses a menu to select the following. (You can also access this menu from the front-panel key

Input Port - Choose between RF, I/Q, I Only, 50 MHz Ref, and IF Align.

•

RF Input Range - To set the RF input range, choose Auto or Manual. If

•

Auto is chosen, the instrument automatically sets the attenuator

based on the power level of the carrier (where the instrument is tuned). If there are multiple carriers present, the total power might overdrive the front end. In this case you need to set the

Range to Manual and enter the expected Max Total Pwr. Manual is also

used if you want to hold the input attenuation constant (for the best relative power accuracy). For single carriers it is generally recommended to set the

Max Total Pwr - To set the maximum total power at the UUT (Unit

•

RF Input Range to Auto.

Under Test). This is the maximum expected value of the mean carrier power referenced to the output of the UUT (may include multiple carriers). The

Atten setting. If RF Input Range is set to Auto, and Max Total Pwr is

changed,

RF Input Range is switched to Manual.

Max Total Pwr setting is coupled to the Input

Input.)

RF Input

Input Atten - To set the input attenuator setting. The Input Atten

• setting is coupled to the Max Total Pwr setting. The Input Atten key reads out the actual hardware value that will be used for the current measurement. If more than one input attenuator value is used in a single measurement, the value used at the carrier frequency will be displayed. If

RF Input Range is switched to Manual.

NOTE The Max Total Pwr and Input Atten settings are coupled together. When

you switch to a different measurement, the constant, but the

RF Input Range is set to Auto, and Input Atten is changed,

Max Total Pwr is kept

Input Atten may change if the two measurements have

different mixer margins. Thus, you can directly set the transmitter tester input attenuation, or you can set it indirectly by specifying the maximum expected power at the UUT (Max Total Pwr setting).

•

Ext Atten - To enter the external attenuator setting for either a BTS

or MS. This will allow the instrument to display the measurement results referred to the output of the UUT (Unit Under Test).

Chapter 2 17

Setting Up the GSM Mode

Changing the Mode Setup

• IF Align Signal - This key has effect only when Input Port is set to IF

Align. When IF Align is activated, the RF path is switched to bring in

the same alignment signal that is automatically switched in to perform many alignments. This selection will allow manual adjustment of the alignment signal for diagnostic purposes:

—

Signal Rate - The signal is modulated by a digital sequence that

can be set to 1 of 13 positions (rate 0 through 12) to cause the comb spacing (or pulse timing) of the alignment signal to widen or narrow. The key reports the comb spacing for a given rate (0 to

12) in “kHz”.

—

Signal Amptd - This is the DAC control that changes the

amplitude of the signal. It is a 12 bit (0 to 4095) DAC. A higher DAC number will raise the signal amplitude.

—

Signal Type - This can be CW (a tone that appears in the center of

the IF),

Comb, or Pulse.

Input Default Settings

Input Port RF RF Input Range Auto Max Total Power −15.00 dBm Input Atten 0.00 dB Ext Atten MS 0.00 dB Ext Atten BTS 0.00 dB IF Align Signal Rate 0 (= 468.75 kHz) IF Align Signal Amptd DAC 500 IF Align Signal Type CW

18 Chapter2

Setting Up the GSM Mode

Changing the Mode Setup

Trigger

The Trigger key accesses the mode setup menu for the following trigger source menus:

•

RF Burst

• Video (IF Envlp)

• Ext Front

• Ext Rear

Pressing one of the trigger source menu keys will access the trigger mode setup menu. This menu is used to set the for each trigger source. Note that the actual trigger source is selected separately for each measurement (under the

Delay - For trigger delay use positive values. For pre-trigger use

negative values.

Level - For the RF Burst selection, the level is relative to the peak

level of the RF signal. For the

Video selection, the level is the value,

in dBm at the RF input, that will cause the trigger. For the and Ext Rear selections, the level range is −5 to +5 volts.

Delay, Level, and Slope

Meas Setup key).

Ext Front

Slope Pos Neg - Choose to trigger off of the leading edge

(

Pos) or the trailing edge (Neg) of the burst.

Other keys accessed under the

Trig Holdoff - Sets the period of time before the next trigger can occur.

•

Auto Trig - Acts as a trigger timeout. If no trigger occurs by the

•

Trigger key:

speciﬁed time, a trigger is automatically generated.

• Frame Timer - Accesses the menu to manually control the frame timer:

Period - Sets the period of the frame clock. Offset - Sets a one-time phase adjustment of the frame clock. Reset Offset - Resets the display of offset key to 0. Sync Source - Selects the source used to sync the frame timer (Ext

Front, Ext Rear, or Off).

Chapter 2 19

Setting Up the GSM Mode

Changing the Mode Setup

• RF Sync Delay - In measurements that detect the GSM “T0”,

RF Sync Delay adjusts the “T0” point. This adjustment does not apply

if the

Burst Sync key is set to None,orifitissettoTraining Seq in the

Phase and Frequency Error measurement. The “T0” point is deﬁned as the time point of the transition from bit 13 to bit 14 of the midamble training sequence for a given time slot.

•

Burst Search Threshold - Sets the threshold level used in the search

for GSMbursts after data is acquired. This is a relative level based on the peak “on” power.

20 Chapter2

RF Burst

Delay Peak Level Slope

Video

Delay Level Slope

Ext Front

Delay Level Slope

Ext Rear

Delay Level Slope

Setting Up the GSM Mode

Changing the Mode Setup

Trigger Default Settings

0.000 s

−20.00 dB Pos

0.000 s

−6.00 dBm Pos

0.000 s

2.00 V Pos

0.000 s

2.00 V Pos

Trig Holdoff 0.000 s Auto Trig 100.0 ms Off

Frame Timer

Period Offset Reset Offset

Sync Source RF Sync Delay 0.000 s Burst Search Threshold −40.00 dB

4.615383 ms

0.000 s Display Off

Demod

• Burst Align - Select the burst alignment between:

GSM- Uses the burst alignment as deﬁned in the GSM

speciﬁcations.

1/2 Bit Offset - Shifts the burst alignment by 1/2 bit. This selection

applies to the Power vs. Time and the Phase and Frequency Error measurements.

Demod Default Settings

Demod Burst Align

Chapter 2 21

GSM

Setting Up the GSM Mode

Changing the Frequency Channel

After selecting the desired mode setup, you will need to select the desired ARFCN, center frequency, BMT frequency, burst type, and TSC (Training Sequence Code). The selections made here will apply to all measurements in the mode. Press the the following menu:

ARFCN Allows you to select the desired RF channel to be

measured. Refer to the table in the previous section for the ARFCN range for a speciﬁc GSM band.

Center Freq This is the current instrument center frequency. Use

this key to input a frequency that corresponds to the desired RF channel to be measured.

BMT Freq Allows you to select the Bottom, Middle, or Top

frequencies of the measured. This will automatically select a speciﬁc center frequency and ARFCN. Refer to the following table.

Frequency Channel key to access

GSM selected radio band to be

Band Tx Band Edge

(MHz)

Low High Freq

P-GSM 935 960 935.200 1 947.600 63 959.800 124 E-GSM 925 960 925.200 975 942.600 38 959.800 124

R-GSM 921 960 921.200 955 940.600 28 959.800 124 DCS 1800 1805 1880 1805.20 512 1842.60 699 1879.80 885 PCS 1900 1930 1990 1930.20 512 1960.00 661 1989.80 810

GSM 450 460.4 467.6 460.600 259 464.000 276 467.400 293 GSM 480 488.8 496.0 489.000 306 492.400 323 495.800 340 GSM 850 869 894 869.200 128 881.600 190 893.800 251

BOTTOM MIDDLE TOP

(MHz)

ARFCN Freq

(MHz)

ARFCN Freq

(MHz)

ARFCN

22 Chapter2

Setting Up the GSM Mode

Changing the Frequency Channel

Timeslot Allows you to select the timeslot to be measured.

Timeslot numbers in the range of 0 to 7 can be selected. Selection of the Timeslot is based on the position on the screen−that is Timeslot 0 is deﬁned to be at the start of the data, and the data is divided into 8 timeslots (0 to

7). This key will be unavailable (grayed out) if a burst type other than

Burst Type Choose a GSM burst type from the following selections:

Normal (TCH & CCH) - Burst length = 142 symbols

•

Sync (SCH) - Burst length = 142 symbols

•

Access (RACH) - Burst length = 88 symbols

TSC Allows you to select the Training Sequence Code that

Normal is selected.

determines which burst is tobemeasured.Thiskeywill be unavailable (grayed out) if a burst type other than

Normal is selected, indicating the standard TSC is used

corresponding to the burst type.

•

Auto - In auto, the measurement is made on the ﬁrst

burst found to have any one of the valid TSCs in the range of 0 to 7. The measurement may be made on various timeslots if more than one timeslot has one of the 8 valid TSCs.

•

When the

GSM mode is selected, the instrument will default to the

following settings.

Function Factory Default Setting

ARFCN >251 Center Frequency 942.600 MHz Timeslot 0 Off Burst Type Normal

TSC (Std) 0 Auto

Man - In manual, the measurement is made on the

ﬁrst burst found to have the selected TSC. TSC numbers in the range of 0 to 7 can be selected. The measurement may be made on various timeslots if more than one timeslot has this same TSC.

(TCH & CCH)

Chapter 2 23

Setting Up the GSM Mode

GSM Measurement Key Flow

The key ﬂow diagrams, shown in a hierarchical manner on the following pages, will help the user to grasp the overall functional relationships for the front-panel keys and the softkeys displayed at the extreme right side of the screen. The diagrams are:

“Mode Setup / Frequency Channel Key Flow” on page 25 “Transmit Power Measurement Key Flow” on page 26 “Power vs. Time Measurement Key Flow” on page 27 “Phase and Frequency Error Measurement Key Flow” on page 28 “Output RF Spectrum Measurement Key Flow” on page 29 “Spectrum (Freq Domain) Measurement Key Flow (1 of 3)” on

page 30 “Waveform (Time Domain) Measurement Key Flow (1 of 2)” on

page 33

View/Trace

QPSK EVM

Avg Number 10 On|Off

“Tx Band Spur Measurement Key Flow” on page 35

Use these ﬂow diagrams as follows:

• There are some basic conventions: An oval represents one of the front-panel keys. This box represents one of the softkeys displayed. This represents an explanatory description on its speciﬁc key. This box represents one of the default condition softkeys displayed.

Default conditions are shown as much as possible with underlined parameters or values displayed on those softkey labels.

• Follow the measurement diagram from left to right and top to bottom.

• A single softkey may allow multiple choices. For example; the softkey reveals two choices, BTS or MS. The underlined choice is the current state of the instrument. To change choices, press the softkey one time.

• When entering a numeric value of

Frequency, for example, use the

numeric keypad and terminate the entry with the appropriate unit selection from the softkeys displayed.

Device

• When entering a numeric value of numeric keypad and terminate with the

Slot (Std), for example, use the

Enter front-panel key.

• Instead of using the numeric keypad to enter a value, it may be easier to use the RPG knob or Up/Down keys.

24 Chapter2

Figure 2-1 Mode Setup / Frequency Channel Key Flow

GSM or EDGE w/GSMMode

Mode Setup

Frequency Channel

Radio

Band P-GSM, E-GSM, R-GSM, DCS 1800, PCS 1900, GSM 450, GSM 480, GSM 850 Device BTS | MS

BTS Type Normal, Micro, Pico

Freq Hopping On |Off

Carrier Burst | Cont

Input

Input Port RF, I/Q, I only, 50 MHz Ref, IF Align

RF Input Range Auto| Man Max Total Pwr Input Atten Ext Atten

MS 0.00 dB BTS 0.00 dB

IF Align Signal

Signal Rate Signal Amptd

Signal Type CW, Comb, Pulse

Trigger

RF Burst

Delay Peak Level Slope Pos| Neg

Video (IF Envlp)

Delay Level Slope Pos| Neg

Ext Front

Delay Level

Slope Pos| Neg

Ext Rear

Delay Level Slope Pos| Neg

Trig Holdoff

Auto Trig 100.0 ms On | Off

Frame Timer

Period Offset Reset Offset Display

Sync Source Off, Ext Front, Ext Rear

RF Sync Delay

Burst SearchThreshold

Demod

Burst Align

GSM

1/2 Bit Offset

ARFCN

Center Freq

BTM Freq Top, Middle, Bottom

Timeslot On | Off

Burst Type Normal, Sync, Access

TSC (Std) 0 Auto | Man

Setting Up the GSM Mode

GSM Measurement Key Flow

Chapter 2 25

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-2 Transmit Power Measurement Key Flow

Measure

Transmit Pwr

Meas Setup

Transmit PwrMeasure

Marker

Averages 50 On | Off Avg Mode Exp | Repeat Avg Type

Pwr Avg (RMS) Log-Pwr Avg (Video) Maximum Minimum

Threshold Lvl -6.00 dB Abs |Rel

Trig Source

Free Run (Immediate) Video (IF Envlp) RF Burst (Wideband) Ext Front Ext Rear

Frame

Burst Sync None

Meas Time 1 Slot

Restore Meas Defaults

Advanced

RBW Filter Gaussian | Flat

Res BW 500.000 kHz

Select 1 | 2 | 3 | 4 Normal

Delta

Function

Band Power

Noise

Off

Trace

RF Envelope

I/Q Waveform

Off

Shape

Diamond

Line

Square

Cross

Marker All Off

26 Chapter2

Figure 2-3 Power vs. Time Measurement Key Flow

Setting Up the GSM Mode

GSM Measurement Key Flow

Measure

Pwr vs Time

Meas Setup

Pwr vs TimeMeasure

View/Trace

Avg Bursts 10On | Off Avg Mode Exp | Repeat Avg Type

Pwr Avg (RMS)

Log-Pwr Avg (Video) Maximum Minimum

Meas Time 1 Slot

Trig Source

Free Run (Immediate)

Video (IF Envlp)

RF Burst (Wideband) Ext Front Ext Rear

Frame

Burst Sync

Training Seq RF Amptd

Restore Meas Defaults

Advanced

RBW Filter Gaussian | Flat Res BW 508.000 kHz

Burst

Rise & Fall

Pwr vs TimeMeasure

Marker

Select 1 | 2 | 3 | 4 Normal

Delta

Function

Band Power

Noise

Off

Trace

RF Envelope

Upper Mask

Lower Mask

Off

Shape

Diamond Line

Square

Cross

Marker All Off

Chapter 2 27

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-4 Phase and Frequency Error Measurement Key Flow

Measure

Phase & Freq

Meas Setup

Phase & FreqMeasure

View/Trace

Phase & FreqMeasure

Marker

Avg Bursts 10On | Off

Avg Mode Exp | Repeat

Avg Type

Mean

Maximum

Trig Source

Free Run (Immediate)

Video (IF Envlp)

RF Burst (Wideband) Ext Front Ext Rear

Frame

Burst Sync

Training Seq RF Amptd

Restore Meas Defaults

I/Q Error (Quad-View)

I/Q Measured Polar Vector Data Bits

Select 1 | 2 | 3 | 4

Normal

Delta

Function

Band Power

Noise

Off

Trace

Phase Error

Phase Error w/Freq

RF Envelope

Off

Shape

Diamond

Line

Square

Cross

Marker All Off

28 Chapter2

Figure 2-5 Output RF Spectrum Measurement Key Flow

Setting Up the GSM Mode

GSM Measurement Key Flow

Measure

Output RF Spectrum

Meas Setup

Output RF SpectrumMeasure

View/Trace

Avg Bursts 20 On | Off Avg Mode Exp | Repeat

Meas Method

Meas Type

Ofs Freq List

Fast Avg On Off

Restore Meas Defaults

Advanced

Modulation Numeric

Multi-Offset

Single Offset (Examine)

Mod & Switch Modulation

Switching

Standard Short Custom

Mod Avg

Pwr Avg (RMS)

Log-Pwr Avg (Video)

Modulation Meas BWs

Carrier RBW 30.000 kHz

< 1800 kHz Offset RBW 30.000 kHz

>= 1800 kHz Offset RBW 100.000 kHz

Switching Meas BWs

Carrier RBW 300 kHz

< 1800 kHz Offset RBW 30.000 kHz

>= 1800 kHz Offset RBW 30.000 kHz

Direct Time Break Freq 600.000 kHz

Output RF SpectrumMeasure

Marker

Select 1 | 2 | 3 | 4 Normal

Delta

Function

Band Power

Noise

Off

Trace

RF Envelope Modulation RF Envelope Switching

Off

Shape

Diamond Line

Square

Cross

Marker All Off

Chapter 2 29

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-6 Spectrum (Freq Domain) Measurement Key Flow (1 of 3)

Measure

Spectrum (Freq Domain)

Meas Setup

Span 1.00000 MHz Res BW 20.0000 kHz Auto| Man Average

Trig Source

Restore Meas Defaults

Advanced

Avg Number 25 On| Off Avg Mode Exp | Repeat

Avg Type

Pwr Avg (RMS)

Log-Pwr Avg (Video)

Voltage Avg

Maximum

Minimum

Free Run (Immediate)

Video (IF Envlp)

RF Burst (Wideband)

Ext Front

Ext Rear Frame

Line

Pre-ADC BPF On | Off

Pre-FFT Fltr Gaussian |Flat

Pre-FFT BW 1.55000 MHz Auto| Man

FFT Window Flat Top (High Amptd Acc)

Flat Top (High Amptd Acc)

Uniform

Hanning

Hamming Gaussian (Alpha 3.5) Blackman Blackman-Harris K-B 70 dB (Kaiser-Bessel) K-B 90 dB (Kaiser-Bessel)

K-B 110 dB (Kaiser-Bessel)

FFT Size

Length Ctrl Auto | Man Min Pnts/RBW

(a)

30 Chapter2

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-7 Spectrum (Freq Domain) Measurement Key Flow (2 of 3)

(a)

ADC Range

Auto Auto Peak

AutoPeakLock

Manual

-6 dB 0 dB

+6 dB +12 dB +18 dB +24 dB

Data Packing Auto, Short, Medium, Long ADC Dither Auto On Off Decimation 0 Auto Man IF Flatness On Off

Spectrum (Freq Domain)Measure

View/Trace

Spectrum

Span X Scale

Span

Amplitude Y Scale

Scale/Div Ref Value Ref Position Top| Ctr | Bot

Scale Coupling On | Off

I/Q Waveform

Span X Scale

Scale/Div

Ref Value

Ref Position Left | Ctr | Right

Scale Coupling On | Off

Amplitude Y Scale

Scale/Div

Ref Value

Ref Position Top | Ctr | Bot

Scale Coupling On |Off

Trace Display

All

Average (or Max & Min)

Current

Chapter 2 31

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-8 Spectrum (Freq Domain) Measurement Key Flow (3 of 3)

Spectrum (Freq Domain)Measure

Marker

Select 1 | 2 | 3 | 4

Normal

Delta

Function

Band Power

Noise

Off

Trace

Spectrum

Spectrum Avg

I/Q Waveform

Off

Shape

Diamond

Line

Square

Cross

Marker All Off

32 Chapter2

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-9 Waveform (Time Domain) Measurement Key Flow (1 of 2)

Measure

Waveform (Time Domain)

Meas Setup

Sweep Time Res BW

Average

Avg Number 10 On| Off Avg Mode Exp | Repeat

Avg Type

Trig Source

Free Run (Immediate) Video (IF Envlp) RF Burst (Wideband) Ext Front Ext Rear Frame Line

Restore Meas Defaults

Advanced

Pre-ADC BPF On | Off

RBW Filter Gaussian | Flat

ADC Range

Pwr Avg (RMS)

Log-Pwr Avg (Video)

Maximum

Minimum

Auto

Auto Peak AutoPeakLock

Manual

-6 dB 0 dB

+6 dB +12 dB +18 dB +24 dB

Chapter 2 33

Setting Up the GSM Mode

GSM Measurement Key Flow

Figure 2-10 Waveform (Time Domain) Measurement Key Flow (2 of 2)

Waveform (Time Domain)Measure

View/Trace

Waveform (Time Domain)Measure

Marker

RF Envelope

Span X Scale

Scale/Div Ref Value Ref Position Left| Ctr | Right Scale Coupling On | Off

Amplitude Y Scale

Scale/Div Ref Value Ref Position Top| Ctr| Bot Scale Coupling On | Off

I/Q Waveform

Span X Scale

Scale/Div

Ref Value Ref Position Left| Ctr | Right Scale Coupling On | Off

Amplitude Y Scale

Scale/Div

Ref Value

Ref Position Top |Ctr | Bot

Scale Coupling On | Off

Select 1 | 2 | 3 | 4 Normal Delta

Function

Band Power

Noise

Off

Trace

RF Envelope

I/Q Waveform

Off

Shape

Diamond

Line

Square

Cross

Marker All Off

34 Chapter2

Figure 2-11 Tx Band Spur Measurement Key Flow

Setting Up the GSM Mode

GSM Measurement Key Flow

Measure

Tx Band Spur

Meas Setup

Tx Band SpurMeasure

Marker

Avg Number 30 On| Off

Avg Mode Exp | Repeat

Avg Type

Pwr Avg (RMS) Log-Pwr Avg (Video)

Maximum Meas Type Examine Full Limit -36.00 dBm dBc

Restore Meas Defaults

Select 1 | 2 | 3 | 4

Normal

Delta

Function

Band Power

Noise

Off Trace

Spectrum Upper Limit

Off

Shape

Diamond

Line

Square

Cross

Marker All Off

Chapter 2 35

Setting Up the GSM Mode

Installing Optional Measurement Personalities

When you Install a measurement personality, you follow a two step process.

1. Install the measurement personality ﬁrmware into the instrument. (See the supplied installation instructions.)

2. Enter a license key number to enable the measurement personality. (Refer to the “License Key Numbers” section below.)

Adding additional measurement personalities requires purchasing a retroﬁt kit for the desired option. The retroﬁt kit contains the measurement personality ﬁrmware. A license key certiﬁcate is also included in the kit. It documents the license key number that is for your speciﬁc option and instrument serial number. Installation instructions are included with the retroﬁt kit.

The installation instructions require you to know three pieces of information about your instrument: the amount of memory installed, the Host ID, and the instrument serial number.

Required information: Key Path: Instrument

Memory: __________________ Host ID:

__________________ Instrument

Serial Number: __________________

System, File System

(the amount of memory in your instrument will be the sum of the memory and the Free memory)

System, Show System, Host ID

System, Show System, Serial Number

Used

The Exit Main Firmware key is used during the ﬁrmware installation process. This key is only for use when you want to update ﬁrmware using a LAN connection. The

Exit Main Firmware key halts the operation

of the instrument ﬁrmware so you can install an updated version of ﬁrmware using a LAN connection. Instructions for loading future ﬁrmware updates are available at the following URL:

www.agilent.com/ﬁnd/vsa/

36 Chapter2

Setting Up the GSM Mode

Installing Optional Measurement Personalities

Available Personality Options

The option designation consists of three characters, as shown in the

Option column of the table below.

Available Personality Options

GSM measurement personality BAH EDGE (with GSM) measurement personality

cdmaOne measurement personality BAC NADC, PDC measurement personalities BAE iDEN measurement personality HN1 W-CDMA measurement personality BAF cdma2000 measurement personality B78

Option

202

a. Available as of the print date of this guide. b. For instruments that already have Option BAH licensed,

order E4406AU Option 252 to add EDGE (with GSM).

License Key Numbers

Measurement personalities purchased with your instrument have been installed and enabled at the factory. You will receive a unique License Key number with every measurement personality purchased. The license key number is a hexadecimal number that is for your speciﬁc measurement personality and instrument serial number. It enables you to install, or reactivate that particular personality.

Follow these steps to display the unique license key number for the measurement personality that is installed in your instrument:

1. Press

System, Install, Choose Option. The Choose Option key accesses

the alpha editor. Use the alpha editor to enter letters (upper-case) and the front-panel numeric keys to enter digits for a personality option that is already installed in the instrument.

2. Press the number for your instrument will now appear on the

Done key on the alpha editor menu. The unique license key

License Key

softkey.

Chapter 2 37

Setting Up the GSM Mode

Installing Optional Measurement Personalities

You will want to keep a copy of your license key number in a secure location. Please enter your license key numbers below for future reference. If you should lose your license key number, call your nearest Agilent Technologies service or sales ofﬁce for assistance.

License Key Numbers for Instrument with Serial # ________

For Option______________ the license key number is _____________________ For Option______________ the license key number is _____________________ For Option______________ the license key number is _____________________ For Option______________ the license key number is _____________________ For Option______________ the license key number is _____________________ For Option______________ the license key number is _____________________

If you purchase an option later, you will receive a certiﬁcate that indicates the unique license key number that you will need to install that option on your particular serial number instrument.

NOTE You will need to enter a license key number only if you purchase an

additional measurement personality at a later date, or if you want to reactivate a measurement personality that has been deactivated.

Installing a License Key Number

NOTE Follow this procedure to reinstall a license key number which has been

deleted during the uninstall process, or lost due to a memory failure. Toinstall a license key number for the selected option, use the following

procedure:

1. Press the alpha editor menu. Use the alpha editor to enter letters (upper-case) and the front-panel numeric keys to enter numbers for the option designation. Then press the option, you will see your entry in the active function area of the display.

Note: that you must already have entered the license key for the GSM option BAH before you can enter the license key for the EDGE retroﬁt option 252.

System, Install, Choose Option. The Choose Option key accesses

Done key. As you enter the

2. Press License Key. Use the alpha editor to enter letters and the front-panel numeric keys to enter digits. You will see your entry in the active function area of the display. When you have completed entering the license key number, press the

38 Chapter2

Done key.

Setting Up the GSM Mode

Installing Optional Measurement Personalities

3. Press the Install Now key after you have entered the personality option number and the license key number. On some instruments, a message may appear in the function area of the display which reads, “Insert disk and power cycle the instrument”. Disregard this message. If you want to proceed with the installation, press the

Yes key and cycle the instrument power off and then on. Press the No

key if you wish to cancel the installation process.

Using the Uninstall Key

The following procedure removes the license key number for the selected option. This will make the option unavailable for use, and the message “Application Not Licensed” will appear in the Status/Info bar at the bottom of the display. Please write down the 12-digit license key number for the option before proceeding. If that measurement personality is to be used at a later date you will need the license key number to reactivate the personality ﬁrmware.

NOTE Using the Uninstall key does not remove the personality from the

instrument memory, and does not free memory to be available to install another option. If you need to free memory to install another option, refer to the instructions for loading ﬁrmware updates located at

www.agilent.com/ﬁnd/vsa/

1. Press Pressing the

System, More(1 of 3), More(2 of 3), Uninstall, Choose Option.

Choose Option key will activate the alpha editor menu.

Use the alpha editor to enter the letters (upper-case) and the front-panel numeric keyboard to enter the digits (if required) for the option, then press the

Done key. As you enter the option, you will see

your entry in the active function area of the display.

2. Press the Uninstall Now key after you have entered the personality option. Press the process. Press the

Yes key if you want to continue the uninstall

No key to cancel the uninstall process.

3. Cycle the instrument power off and then on to complete the uninstall process.

Chapter 2 39

Setting Up the GSM Mode

Installing Optional Measurement Personalities

40 Chapter2

3 Making GSM Measurements

Making GSM Measurements

GSM Measurements

Once in the mode, the following measurements for the GSM 450, GSM 480, GSM 850, GSM 900, DCS 1800, and PCS 1900 bands are available by pressing the

❏ Transmit Power on page 49 ❏ Power vs. Time on page 54 ❏ Phase and Frequency Error on page 59 ❏ Output RF Spectrum on page 66 ❏ Spectrum (Frequency Domain) on page 78 ❏ Waveform (Time Domain) on page 86 ❏ Tx Band Spur on page 93

These are referred to as one-button measurements. When you press the key to select the measurement it will become the active measurement, using settings and a display unique to that measurement. Data acquisitions will automatically begin provided trigger requirements, if any, are met.

Measure key.

42 Chapter3

Making GSM Measurements

Preparing for Measurements

If you want to set the GSM mode to a known, factory default state, press

Preset. This will preset the mode setup and all of the

measurements to the factory default parameters.

NOTE Pressing the Preset key does not switch instrument modes.

To preset only the settings that are speciﬁc to the selected measurement, press set the measure setup parameters, for the currently selected measurement only, to the factory defaults.

Initial Setup

Before making a measurement, make sure the mode setup and frequency/channel parameters are set to the desired settings. Refer to the sections “Changing the Mode Setup” and “Changing the Frequency

Channel” in the previous chapter.

Meas Setup, More, Restore Meas Defaults. This will

How to Make a Measurement

Follow the three-step process shown in the table below:

Step Primary Key Setup Keys Related Keys

1. Select & setup a mode

2. Select & setup a measurement

3. Select & setup view

Mode Mode Setup, Input,

Frequency Channel

Measure Meas Setup Meas Control,

View/Trace Span X Scale,

Amplitude Y Scale Next Window, Zoom

, Display,

System

Restart File

, Save,

Print, Print Setup, Marker, Search

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Making GSM Measurements

Preparing for Measurements

Measurement Control

The Meas Control front panel menu key controls processes that affect the running of the current measurement.

•

Measure softkey. Press Meas Control,Measure (nottobe confused with

the front panel between Single and Cont (for continuous) measurement states. When set to Single, the measurement will continue until it has reached the speciﬁed number of averages set by the average counter. When set to Continuous, the measurement will run continuously, and perform averaging according to the current average type (repeat or exponential). The default setting is continuous.

•

Pause key. Press Meas Control, Pause to pause the current

measurement. Once toggled, the label of the read

Resume. The Resume key, once pressed, continues the active

measurement from the point at which it was paused.

• Restart key. The Restart front panel key repeats the current measurement from the beginning, while retaining the current measurement settings.

Measure key which has a different function) to toggle

Pause key changes to

44 Chapter3

Making GSM Measurements

Preparing for Measurements

Measurement Setup

The Meas Setup key accesses features that enable you to adjust parameters of the current measurement, such as resolution bandwidth. You will also use the and

Advanced measure setup feature menus.

The following measure setup features can be used with many or all measurements.

Res BW key. Press Meas Setup, Res BW to change the resolution of a

• given measurement. Selection of a narrower bandwidth will result in a longer data acquisition time.

•

Restore Meas Defaults key. To preset only the settings that are

speciﬁc to the selected measurement, press

Restore Meas Defaults. This will set the measure setup parameters,

for the currently selected measurement only, to the factory defaults.

Averaging

Meas Setup menutoaccesstheAverage, Trig Source,

Meas Setup, More,

Selecting one of the averaging keys in the

Meas Setup menu will allow

you to modify the number, averaging mode, and type of averaging you use for the currently selected measurement.

•

Averages, or Avg Number - Allows you to change the number of N

averages to be made.

• Avg Mode Exp Repeat - Allows you to choose either exponential or repeat averaging. This selection only effects the averaging after the number of N averages is reached (set using the

Avg Bursts, or Avg Number key).

Averages,

— Normal averaging: Normal (linear) averaging is always used

until the speciﬁed number of N averages is reached. When

Measure is set at Single, data acquisitions are stopped when the

number of averages is reached - thus

Avg Mode has no effect on

single measurements.

— Exponential averaging: When Measure is set at Cont, data

acquisitions will continue indeﬁnitely. After N averages, exponential averaging is used with a weighting factor of N (the displayed average count stops at N). Exponential averaging weights new data more than old data, which allows tracking of slow-changing signals. The weighting factor N is set using the

Averages, Avg Bursts, or Avg Number key.

— Repeat averaging: When

Measure is set at Cont, data

acquisitions will continue indeﬁnitely. After N averages is reached, all previous result data is cleared and the average count is set back to 1. This is equivalent to being in pressing the

Restart key each time the Single measurement

Measure Single and

ﬁnishes.

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Making GSM Measurements

Preparing for Measurements

• Avg Type - Select the averaging type from the following selections: (Not all of the selections are available for all measurements)

Pwr Avg (RMS) - The true power averaging, and is equivalent to

taking the RMS of the voltage. It is the most accurate type.

Log-Pwr Avg(Video) - Simulates the traditional spectrum analyzer

type of averaging by averaging the log of the power.

Mean - Averages the mean values. Voltage Avg - Averages the voltage values. Maximum - Keeps track of the maximum values. Minimum - Keeps track of the minimum values.

Max & Min - Keeps track of the maximum and minimum values.

46 Chapter3

Trig Source

Making GSM Measurements

Preparing for Measurements

Changing the selection in the

Trig Source menu alters the trigger source

for the selected measurement only. Not all of the selections are available for all measurements. Note that the

Video (IF Envlp), Ext Front, and Ext Rear menu keys found in the Trigger

RF Burst (Wideband),

menu enable you to change settings to modify the delay, level, and slope for each of these trigger sources. Choose one of the following trigger sources:

•

Free Run (Immediate) - The trigger occurs at the time the data is

requested, completely asynchronous to the RF or IF signal.

• RF Burst (Wideband) - An internal wideband RF burst trigger that has an automatic level control for burst signals. It triggers on a level that is relative to the peak of the signal passed by the RF.

•

Video (IF Envlp) - An internal IF envelope trigger. It triggers on an

absolute threshold level of the signal passed by the IF.

• Ext Front - Activates the front panel external trigger input (EXT

TRIGGER INPUT). The external trigger must be a signal between −5

and +5 volts.

• Ext Rear - Activates the rear panel external trigger input (TRIGGER

IN). The external trigger must be a signal between −5 and +5 volts. Frame - Uses the internal frame clock to generate a trigger signal.

• The clock parameters are controlled under the

Mode Setup key or the

measurement ﬁrmware, not both. See the speciﬁc measurement for details.

•

Line - activates an internal line trigger. Sweep triggers occur at

intervals synchronized to the line frequency.

Rear panel TRIGGER 1 OUT and TRIGGER 2 OUT connectors are coupled to the selected trigger source. These trigger outputs are always on the rising edge with a pulse width of at least 1 µs.

Chapter 3 47

Making GSM Measurements

Preparing for Measurements

Burst Sync

Pressing the

Burst Sync key allows you to choose the source used to

synchronize the measurement to the “T0” point of the GSM burst. The “T0” point is deﬁned as the time point of the transition from bit 13 to bit 14 of the midamble training sequence for a given time slot. The

Burst Search Threshold setting (in the Mode Setup keys under Trigger)

applies to both Pressing the

Training Seq and RF Amptd. It is described on page 20.

Burst Sync key will bring up a menu with some or all of the

following choices:

•

Training Seq - Synchronizes the measurement to the timing of the

demodulated training sequence in the GSM burst. This is the most precise method, but requires a GSM burst with a valid TSC (Training Sequence Code). The “T0” point is determined by demodulation of the burst and successful identiﬁcation of the TSC. “T0” is then found to within 1/10 bit.

•

RF Amptd - Synchronizes the measurement to the burst transition of

the measured RF carrier. “T0” is set to the 50% point between the start and end of the burst.

•

None - Use the start of the time record as the start of the useful part.

“T0” is set to the middle of the useful part.

• Ext - Use the external trigger plus delay as the start of the useful part. “T0” is set to the middle of the useful part.

48 Chapter3

Making GSM Measurements

Making the Transmit Power Measurement

Purpose

Transmit Power is the measure of in-channel power for GSM systems. Mobile stations and base transceiver stations must transmit enough power, with sufﬁcient modulation accuracy, to maintain a call of acceptable quality without leaking into frequency channels or timeslots allocated for others. GSM systems use dynamic power control to ensure that each link is maintained with minimum power. This gives two fundamental beneﬁts: overall system interference is kept to a minimum and, in the case of mobile stations, battery life is maximized.

The Transmit Power measurement determines the average power for an RF signal burst at or above a speciﬁed threshold value. The threshold value may be absolute, or relative to the peak value of the signal.

At the base transceiver station, the purpose of the Transmit Power measurement is to determine the power delivered to the antenna system on the radio-frequency channel under test. The Transmit Power measurement veriﬁes the accuracy of the mean transmitted RF carrier power. This can be done across the frequency range and at each power step.

Measurement Method

The instrument acquires a GSM signal in the time domain. The average power level above the threshold is then computed and displayed. This measurement uses the “power-above-threshold” method instead of the “useful part of the burst” method deﬁned in the GSM standards. The measured Transmit Carrier Power will be very nearly the same for these two methods. The power-above-threshold method has the advantages of being faster and allows power measurements to be made at somewhat lower power levels. It also has the advantage of not requiring the carrier to have a valid TSC (Training Sequence Code).

Note that this measurement does not provide a way to specify which timeslot is to be measured. Therefore if multiple timeslots are on, they should all be set at the same power level, or the levels of those timeslots to be excluded need to be kept below the threshold level. If you want to measure Transmit Carrier Power using the GSM speciﬁed useful part of the burst method, use the Power vs. Time measurement, which also measures the power ramping of the burst.

Chapter 3 49

Making GSM Measurements

Making the Transmit Power Measurement

Making the Measurement

NOTE The factory default settings provide a GSM compliant measurement.

For special requirements, you may need to change some of the settings. Press return all parameters for the current measurement to their default settings.

Select the desired ARFCN, center frequency, timeslot, burst type, and TSC (Training Sequence Code) as described in the section titled

“Changing the Frequency Channel” on page 22.

Meas Setup, More (1 of 2), Restore Meas Defaults at any time to

Press

Measure, Transmit Pwr to immediately make Transmit Power the

active measurement. Tochange any of the measurement parameters from the factory default

values, refer to the “Changing the Measurement Setup” section for this measurement.

50 Chapter3

Making the Transmit Power Measurement

Results

Figure 3-1 Transmit Power Result - Single Burst

Making GSM Measurements

Figure 3-2 Transmit Power Result - Multiple Bursts

Chapter 3 51

Making GSM Measurements

Making the Transmit Power Measurement

Changing the Measurement Setup

Table 3-1 Transmit Power Measurement Defaults

Measurement Parameter Factory Default Condition

Averages 50 On Avg Mode Exp Avg Type Pwr Avg (RMS) Threshold Lvl −6.00 dB Rel (to peak) Trig Source RF Burst (Wideband) Burst Sync None Meas Time 1 slot

Advanced

RBW Filter Gaussian Res BW 500.000 kHz

NOTE Parameters that are under the Advanced key seldom need to be

changed. Any changes from the factory default values may result in invalid measurement data.

Make sure the Transmit Power measurement is selected under the

Measure menu. Press the Meas Setup key to access a menu which allows

you to modify the averaging, trigger source, and burst sync for this measurement (as described in the “Measurement Setup” section at the beginning of this chapter). In addition, the following transmit power measurement parameters can be modiﬁed:

•

Threshold Lvl Abs Rel - choose absolute or relative and enter a value

for the threshold level. The absolute value sets the threshold line at that power level. The relative value will set the threshold line at a speciﬁed level relative to the peak of the burst. The measurement will determine the average power of all data above this threshold.

•

Burst Sync - an information only key. The selection cannot be

changed for this measurement.

• Meas Time - allows you to measure more than one timeslot. Enter an integer value in increments of “slots” with a range of 1 to 50. The actual measure time is set somewhat longer than the speciﬁed number of slots in order to view the complete burst.

52 Chapter3

Making GSM Measurements

Making the Transmit Power Measurement

• Advanced - accesses a menu to change the following parameters:

RBW Filter - this key toggles to select a Flat Top or a Gaussian (the

default ﬁlter) resolution bandwidth ﬁlter. A Gaussian ﬁlter provides more even time domain response,particularlyforbursts. A Flat Top ﬁlter provides a ﬂatter bandwidth but is less accurate for pulse responses. A Flat Top ﬁlter also requires less memory and allows longer data acquisition times.

Res BW - sets the resolution bandwidth.

Troubleshooting Hints

Low output power can lead to poor coverage and intermittent service for phone users. Out of speciﬁcation power measurements indicate a fault usually in the power ampliﬁer circuitry. They can also provide early indication of a fault with the power supply, i.e. the battery in the case of mobile stations.

Chapter 3 53

Making GSM Measurements