Analysis of Plain and Diversity Combining Hybrid ARQ Protocols over the m(>=2)-ary Asymmetric Channel

In the automatic repeat request (ARQ) protocol, the sender keeps retransmitting a code word until it receives a positive acknowledgment from the receiver sent through the feedback channel. This correspondence proposes plain and diversity combining hybrid ARQ protocol communication schemes suitable for the m(>=2)-ary asymmetric channel using t-asymmetric error correcting/all asymmetric error detecting (t-AEC/AAED) codes. The analysis shows that error correction definitely improves the throughput of the system compared to the ARQ protocol which uses only error detecting codes. The correspondence provides simple analytic expressions for the average number of transmissions of a code word in both plain and diversity combining t-AEC/AAED ARQ (t >=0) protocol systems over the m-ary asymmetric channel, m>=2. An example is shown on how to get very close to the Z-channel capacity.[...