PERFORMANCE STUDY OF SOFT-HANDOFF EFFECT AND MULTI-CHANNEL ACCESS SCHEMES IN CDMA CELLULAR SYSTEMS

摘要

The CDMA system promisingly provides more capacity than AMPS. Multi-channel mechanism becomes an inevitable trend for CDMA systems when cell traffic is markedly higher than that of single-channel CDMA systems. Two multi-channel assignment schemes with soft handoff effect and corresponding channel selection rules are discussed herein and performance measures, e.g. blocking probabilities, the overall system capacity, and the capacity of each channel with respect to various channel assignment schemes, are obtained and compared. Since the same frequency channel may be assigned to two adjacent cells, effect of soft handoff is also considered which can enhance system capacity. Simulation results indicate that SIR based selection scheme is preferable to the other scheme.