| Current cellular systems typically have spectral efficiency in the range of 0.03–0.05 b/s/Hz/sector and the talk time is about 3 hours. The dramatic increase in demand for high speed wireless data services requires the next generation wireless networks to significantly improve the throughput and energy efficiency while maintaining a reasonable delay. In this thesis, we investigate rate adaptive coding and automatic repeat request (ARQ) schemes to meet these new challenges.; An analytical framework is investigated for performance evaluation of general type-I and type-II hybrid ARQ protocols based on rate compatible error correcting codes over finite-state channels. As an example, an analysis of Reed-Solomon code based systems is shown to yield insight into the effect of the protocols, channel parameters, design parameters, and decoder implementations on the system performance. A family of powerful rate compatible multiple product codes are constructed and shown to have superior performance compared with S-random interleaved turbo codes at moderate signal-to-noise ratio. A few practical rate adaptive ARQ protocols are then applied to an asynchronous direct-sequence code division multiple access network and compared in terms of the total network throughput, average delay, and throughput under energy constraints. |
