Mobile-location aware rate adaptive unslotted CLSP/DS-CDMA PRN: performance in a heavily-correlated fading channel

The paper presents a throughput-delay analysis of an unslotted DS-CDMA packet radio network (PRN) using a mobile-location aware rate adaptive channel load sensing protocol (CLSP) for media access control (MAC) in a heavily correlated Rayleigh fading channel. In this adaptive CLSP scheme, which we proposed previously (see Phan, V.V. and Glisic, S., IEEE ICC´02, 2002), an uncorrelated fading model is used for investigating system performance. This paper shows that while the error-correcting capability of channel coding has not yet been effective in heavily-correlated fading environments, the rate adaptive CLSP still provides significant enhancement for efficiency of radio and battery resource utilization compared to the fixed rate counterpart. Through our modeling, a comprehensive study is presented of the correlation between fade duration statistics and packet-transmission duration, and the impacts of channel attenuation, user mobility, spatial user distribution (SUD), and transmitter power control (TPC) inaccuracy. This paper lays groundwork for understanding the possibilities and benefits of context-aware adaptation on MAC, the vital layer of PRNs.