30-06-2012, 05:34 PM
CDMA Network Design
CDMA Network Design.ppt (Size: 403.5 KB / Downloads: 49)
Problem Statement
How to match cell design to user distribution for a given number of base stations?
CDMA network capacity calculation
Reverse signal power and power control
Pilot-signal power
Base station location
CDMA Capacity Issues
Depends on inter-cell interference and intra-cell interference
Complete frequency reuse
Soft Handoff
Power Control
Sectorization
Voice activity detection
Graceful degradation
Power Compensation Factor
Fine tune the nominal transmission power of the mobiles
PCF defined for each cell
PCF is a design tool to maximize the capacity of the entire network
Twenty-seven Cell CDMA Network
Uniform user distribution profile.
Network capacity equals 559 simultaneous users.
Uniform placement is optimal for uniform user distribution.
Three Hot Spot Clusters
All three hot spots have a relative user density of 5 per grid point.
Network capacity decreases to 536.
Capacity in cells 4, 15, and 19, decreases from 18 to 3, 17 to 1, and 17 to 9.
Conclusions
Solved cell design problem: given a user distribution, found the optimal location and pilot-signal power of the base stations and the reverse power of the mobiles to maximize network capacity.
Uniform network layout is optimal for uniform user distribution.
Combined optimization increases network capacity significantly for non-uniform user distribution.