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CDMA Spectral Efficiency. Enhancing 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. Handset. Spectral Efficiency techniques. Network.

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Cdma spectral efficiency

CDMA Spectral Efficiency

Enhancing the most secured system

Cdma technology
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


Spectral Efficiency techniques


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
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 (RLIC)

  • Reverse link interference cancellation equally important.

  • Mobile transmits less power .

  • Increase the battery life.

1 8 rate gating on r fch
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

Cdma spectral efficiency

  • 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
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
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
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
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
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


  • A growth of 375% in the traffic capacity.

  • 120 active users per carrier, per sector.

  • Spectral efficiency takes place.