CDMA Spectral Efficiency

CDMA Spectral EfficiencyEnhancing the most secured system

CDMA Technology

CDMA – “Most secured”

Fast growing rate of CDMA subscribers

Evolution of Ev-DO technology in year 2000

Need of spectral efficiency using 1X advance features.

Spectral Efficiency techniques

Network Handset 4GV Vocoders Transmit diversity in Base

Station New Radio Configuration 4-way receive diversity in

Base Station Quasi orthogonal functions 1/8th rate gating on R-FCH RL interference cancellation

4GV Vocoders Receive diversity in mobile

terminals Quasi orthogonal functions New Radio Configuration Quasi-linear interference

cancellation in mobiles Enhanced FL interference

cancellation 1/8th rate gating on R-FCH

Quasi-Linear interference cancellation (QLIC) Pilot consumes sizable

amount of power .

Interference is common.

Important to initialize Pilot Interference Cancelation (PIC) and forward link interference cancelation (FLIC).

Reverse Link Interference cancellation (RLIC)

Reverse link interference cancellation equally important.

Mobile transmits less power .

Increase the battery life.

1/8 rate Gating on R-FCH

It is put “ON” at MSC level MS will gate the R-FCH/R-Pilot Channel when

transmitting at 1/8th rate. Power control factor is achieved

4GV Dynamically prioritize voice quality to increase

network capacity EVRC-B is an enhancement to EVRC Used both at the network as well as in the handset.

Radio Configuration Set of forward traffic channel and reverse traffic

channel Physical layer parameters such as data rates,

modulation characteristics, and spreading rates.

Quasi-Orthogonal functions (QOF) Increasing of the number of users.

Walsh code is limited for much possible users.

QOF process optimal cross-correlation with Walsh code

6 Sectorization Some places with high utilization and

excess softer handoff.

6 sector s one of the solution.

Instead of using 1 BTS, 2 BTS are used

Antenna can be separated from each other at 60 degrees instead of 120 degrees.

Network Optimization

Ec/Io optimization

Forward and reverse link imbalance

Excessive soft handoff areas

Improper RF parameters settings

Use repeaters for low utilized sectors

Antenna Diversity Improve the quality of a wireless link Mitigate these multipath situations Using multiple antennas decreases the number of

drop-outs and lost connections

Conclusion

A growth of 375% in the traffic capacity. 120 active users per carrier, per sector. Spectral efficiency takes place.

Increase in the traffic capacity

Thank You