Throughput analysis for a packet radio network using rate adaptive OFDM signaling

This paper analyzes the throughput for an adaptive packet radio network (PRN). The proposed adaptive OFDM spread spectrum (OFDM-SS) system can trade off system processing gain (i.e. user data rate) for transmission quality under changing channel conditions. Classic throughput analysis for fixed and random access schemes is extended for this proposed adaptive PRN. The focus is on pure-ALOHA and nonpersistent CSMA (NP-CSMA) systems. The paper introduces a method to analyze network throughput with variable packet durations due to variable user data rate. The large improvement from the adaptive system compared to the conventional fixed rate counterpart is demonstrated by various mobile user population profiles and radio propagation path loss models.