Comparison of ARQ protocols for asynchronous data transmission over Rayleigh fading channels

the authors examine error control techniques for the transmission of asynchronous data over Rayleigh fading channels. Type-I hybrid ARQ schemes are considered with rate 1/2 convolutional coding for FEC. The protocols are evaluated over a full rate North American Digital Cellular channel with the goal of achieving 4.8 kbit/s asynchronous data transmission. Throughput and round trip acknowledgment delay (RTAD) results are presented for various vehicle speeds. The Go-Back-N ARQ (GEN-ARQ) protocol, and four different versions of the Selective-Repeat ARQ (SR-ARQ) protocol are compared. The relative performance of the different ARQ protocols is discussed. A version of the selective repeat protocol, which combines the error recovery mechanisms of GBN-ARQ. The pure selective repeat protocol and other enhancements, provides the best compromise in terms of throughput and delay performance over the range of different speeds and SNR conditions