New mapping rules for combination of M-ary modulation and error-detecting codes in ARQ systems

In some automatic repeat request (ARQ) schemes, the combination of modulation and channel coding improves the performance of a communication system. The paper describes a new method for the integration of an error-detecting code with M-ary modulation. Euclidean distances are obtained among modulated signals using successive transmissions of the same codeword larger than those obtained by other similar schemes. The results of the theoretical analysis show that the described method allows improvement of both the error probability and the throughput of an ARQ protocol with respect to other schemes.<>