Qualcomm QCP 2760 User Manual download pdf (Page 5)

cdma2000 pilot channel analysis

The E7477A system measures cdma2000, IS-95 and J-STD-

008 CDMA pilot channels. These measurements are indepen-

dent of network parameter settings. The system executes

four different types of CDMA pilot channel measurements (list-

ed below). Any or all of them can be executed simultaneously.

Measurement types

All pilots:

The system measures the power, both Ec and Ec/Io, of all

512 pilot channels. The results are displayed as a trace with

one point for each of the 512 PN offsets.

Top N:

The system measures all of the pilots in the network and

returns the ‘N’ strongest pilot channels received, where ‘N’

is a user definable integer from 1 to 20. The results are

displayed in bar graph format.

Zoomed pilots:

The user sets the center and span in terms of chips (or

PN offsets). The results are displayed as a trace.

User list:

The user manually inputs a list of up to 20 PN offsets to be

measured. The measurements are displayed in bar graph

format – up to 20 bars.

Measurement controls

• Carrier frequency

Frequency

Channel

• Measurement types

All pilots

Top N pilots

Zoomed pilots

User list of pilots

• PN increment

Display controls

• Power display (Y-axis parameter)

Ec/Io

• Show value (bar graphs only)

Peak Ec/Io

Peak Ec

Aggregate Ec/Io

Aggregate Ec

Aggregate - peak

Delay spread

Pilot delay

Markers (trace displays only)

• Multiple markers

• Delta markers

• To max function

• Drag and drop

Measurement results

• Peak Ec/Io

• Peak Ec

• Io

• Aggregate Ec/Io (TopN and user list only)

• Aggregate Ec (TopN and user list only)

• Aggregate – peak (TopN and user list only)

• Delay spread (TopN and user list only)

• Pilot delay

• Carrier frequency error

Peak pilot power (both Ec and Ec/Io) are computed by

selecting the strongest peak of the correlation for each pilot.

Io is the total received power integrated across the entire

1.2288 MHz signal bandwidth.

Aggregate pilot power (both Ec and Ec/Io) are computed

for a given pilot by integrating the power received over the

time dispersion of that pilot. Delay spread is the duration

of time over which this power is dispersed. Both aggregate

pilot power and delay spread are determined with respect

to an Ec/Io threshold of –17 dB. The system also reports

the difference between the aggregate and peak pilot power

(aggregate-peak). This difference along with the delay

spread provides a characterization of the multipath effect on

that pilot. Aggregate pilot power and delay spread are only

measured for the TopN and user list measurement types.

Pilot delay is defined as the difference in time between

when a pilot signal is received and when it should have been

transmitted, as defined by GPS timing. For example, a base

station transmitting PN offset 0 is expected to start a new

short-code pattern synchronous with the GPS even second

clock. If the signal is received 3 chips after the GPS even

second clock, then the pilot delay is said to be 3 chips

(1 chip at 0.8 microseconds). Timing offsets can be due to

both propagation delay and base station timing problems.

Figure 1. Pilot analyzer

Carrier frequency error is defined as the difference

between the measured carrier frequency and the user-speci-

fied carrier frequency. The measured carrier frequency is of

the dominant pilot signal. Carrier frequency error can be due

to both base station carrier error and doppler shift (if moving).

1 2 3 4 5 6 7 8 9 10 ... 15 16

Comments to this Manuals

No comments

Qualcomm QCP 2760 User Manual Page 5

Comments to this Manuals

Related products and manuals for Mobile phones Qualcomm QCP 2760