Coding Investigation for Time Division Multiple Access Communications.

摘要

The report presents a thorough analysis of the application of coding to a tactical time division multiple access (TDMA) system. Cost and complexity are compared for a variety of candidate coding techniques which provide at least 3dB coding gain over uncoded DPSK at a 0,001bit error rate. The recommended technique,convolutional coding and Viterbi decoding is subjected to a more detailed analysis. In particular, a technique is developed for digitally deriving a channel phase reference for demodulation-decoding from modulated received data. Simulation results showing the performance of this phase measurement technique are presented,as well as a detailed logic design of its implementation. System cost projections are presented for addition of coding to the TDMA system. The interaction between coding and the TDMA system parameters is discussed,with emphasis on accommodation of coding in the proposed TDMA formats with minimum change. The performance degradation in the presence of multipath is also analyzed. (Author)