Performance analysis of a random access direct sequence, packet combining, code division multiple access system

A throughput analysis is presented for a slotted direct sequence code division multiple access (CDMA) radio network using averaged diversity combining (ADC). The probability of packet acceptance is maximized through the combination of multiple received copies of the same data packet. The combining is performed at the bit level according to an averaged diversity rule. Numerical and simulation results indicate that the use of ADC is highly advantageous for systems which tolerate a certain delay and operate over highly time-varying channels. The throughput performance is superior to that of type-I hybrid ARQ slotted CDMA at the expense of more buffer space and a minor modification in the decoding process.