Adaptive coding for mobile ad hoc networks with frequency-hop transmission and soft-decision decoding

Alternative protocols are presented for adapting the code from packet to packet in a mobile, wireless, ad hoc network that employs frequency hopping, coherent or noncoherent demodulation, and soft-decision decoding on channels with time-varying partial-band interference. The protocols are implemented in subsystems that are external to the demodulator and soft-decision decoder, so they can be employed with a wide range of codes and decoding algorithms. No channel measurements are needed and no external side information is supplied to the receiver. Performance results are provided for packet transmissions that employ turbo product codes. Protocol performance is compared with capacity limits and with an ideal protocol that uses perfect channel state information for the most recent packet transmission to select the code that maximizes the expected throughput.