Simulation results of adaptive trellis-coded modulation to achievean increased information rate on the meteor burst channel

摘要

Investigates the performance of an adaptive trellis-codednmodulation (ATCM) meteor burst communications system proposed bynJacobsmeyer [1987, 1989, 1992]. In those papers, Jacobsmeyer developednthe theoretical performance of the system. A simulation was needed tonverify two things about the proposed system: 1) would the Viterbinalgorithm tolerate instantaneous code rate changes when the encoder isnconstructed with rate changing built into the encoder trellis, and 2)nwere the theoretical performance improvements based on asymptotic codingngain calculations valid? It turns out that the Viterbi algorithm can benused in an adaptive trellis-coding scheme to recover coded bitsncontinuously throughout the trail lifetime at more than one informationnrate without loss of decoder trellis path memory. Also, the simulationnresults agreed very well with the theoretical predictions for codingngains and throughput improvement of ATCM over a fixed-rate BPSK system.nAt a bit error rate (BER) of approximately 10^-3, theorynpredicted a throughput improvement upper bound of 3.32, and thensimulation demonstrated an actual improvement of 3.08