A class of block-coded modulation schemes based on one-step partitioning of the signal alphabet

The alphabet expansion that is necessary for coding is smaller than that in Ungerboeck´s trellis-coded modulation (TCM) and previously proposed block-coded-modulation (BCM) schemes. Using short block lengths (2, 3, ad 4), specific modulations that transmit 4, 6 and 8 information bits per symbol are described. The gain over equivalent uncoded modulation is smaller than 3 dB, but their detection simplicity makes the presented BCM schemes very attractive for high-speed applications, where TCM decoders are difficult to implement. In particular, the presented technique is of potential interest to high-capacity digital microwave radio systems. The coding gain is also investigated on nonlinear channels and found to be significantly higher than on additive white Gaussian noise channels