Channel quality estimation and rate adaptation for cellular mobile radio

We propose a technique to measure channel quality in terms of signal-to-int erference plus noise ratio (SINR) for the transmission of signals over fadi ng channels. The Euclidean distance (ED) metric, associated with the decode d information sequence or a suitable modification thereof, is used as a cha nnel quality measure. Simulations show that the filtered or averaged metric is a reliable channel quality measure which remains consistent across diff erent coded modulation schemes and at different mobile speeds. The average scaled ED metric can be mapped to the SINR per symbol. We propose the use o f this SINR estimate for data rate adaptation, in addition to mobile assist ed handoff (MAHO) and power control, We particularly focus on data rate ada ptation and propose a set of coded modulation schemes which utilize the SIN R estimate to adapt between modulations, thus improving data throughput. Si mulation results show that the proposed metric works well across the entire range of Dopplers to provide near-optimal rate adaptation to average SINE, This method of adaptation averages out short-term variations due to Raylei gh fading and adapts to the long-term effects such as shadowing, At low Dop plers, the metric can track Rayleigh fading and match the rate to a short-t erm average of the SINR, thus further increasing throughput.