Zhejiang Sci-Tech University
In the paper, an improved link adaptation scheme is proposed for the Wi-Media MB-OFDM UWB system, in which Quality of Service (QoS) support is provided. The proposed scheme consists of three functional blocks: Link Quality Indicator (LQI) calculator, Frame Error Rate (FER) estimator, and Transmitter (TX) parameter selector. Instead of using the Average receive SNR (ASNR) as LQI, a new LQI metric is defined based on a union bound analysis to capture the effects of both path loss and frequency selectivity of an instantaneous UWB channel. How to calculate LQI for each rate mode is investigated by analyzing the distribution of soft bit information.