Variable-rate coded MQAM for fading channels

Proposes a variable-rate coded modulation technique for narrowband fading channels, where channel state information is available to both the transmitter and receiver. The technique can be applied to either trellis or block codes. The basic premise is to adjust the size of the transmit signal constellation relative to the fade depth via power control. Specifically, channel coding gain is achieved through binary encoding and subset partitioning, while the size of the transmit constellation is adjusted to maximize the data rate. The author presents analytical performance results for the coding technique, and compares it with built-in time diversity coded modulation, which assumes no channel information at the transmitter.

针对窄带衰落信道提出一种可变速率编码调制技术，在该信道中发射机和接收机均可获得信道状态信息。此技术可应用于网格码或分组码。其基本前提是通过功率控制根据衰落深度来调整发射信号星座图的大小。具体而言，通过二进制编码和子集划分来实现信道编码增益，同时调整发射星座图的大小以使数据速率最大化。作者给出了该编码技术的分析性能结果，并将其与内置时间分集编码调制进行比较，后者假定发射机处无信道信息。