Application of turbo codes to tactical communications
A practical multifunctional system comprising a turbo decoder, low complexity turbo equalizer and turbo synchronizer is developed to compensate for frequency-selective channels with fading. The combined synchronizer, equalizer and decoder are based on a turbo scheme where soft extrinsic information is exchanged between these processes and between iterations. The turbo codes are based on Partial Unit Memory Codes, which may be constructed with higher free distance than equivalent recursive systematic convolutional codes and can achieve better performance than the latter. The purely digital multifunctional receiver is targeted for end-applications such as combat-radio and radio-relay, providing robust communication at low signal-to-noise ratio with performance approaching the Shannon limit. This paper presents design considerations for the multifunctional turbo-based receiver as well as simulation results for its performance in combat-radio communications channels.
turbo codes multifunctional systems turbo equalization turbo synchronization