Throughput analysis of adaptive ARQ schemes

Abstract

AbstractMany ARQ error control schemes have been proposed in data transmission, including go‐back‐N and selective‐repeat schemes. In those schemes, most of the parameters affecting performance, such as the number of continuously transmitted data blocks and the data block length, are fixed. Consequently, the performance may be greatly degraded when there is a time‐variation in the bit‐error rate or when the bit‐error rate is difficult to estimate. This paper proposes a control scheme wherein the number of continuously transmitted data blocks and the data block length are adapted dynamically to the bit‐error rate. The throughput of the proposed scheme is analyzed for go‐back‐N and selective‐repeat schemes using the half‐duplex channel. The evaluations for the go‐back‐N and the selective‐repeat schemes are obtained as special cases of the result of analysis. The effects of various parameters on performance are discussed and the performances of various schemes are compared. The results show that the proposed scheme based on the adaptive control has a performance which is very close to the scheme with a fixed number of continuously transmitted data blocks and fixed data block length, where those parameters are set optimally in a static way.