Power and Bandwidth Efficient Coded Modulation for Linear Gaussian Channels

A scheme for power- and bandwidth-efficient communication on the linear Gaussian channel is proposed. A scenario is assumed in which the channel is stationary in time and the channel characteristics are known at the transmitter. Using interleaving, the linear Gaussian channel with its intersymbol interference is decomposed into a set of memoryless subchannels. Each subchannel is further decomposed into parallel binary memoryless channels, to enable the use of binary codes. Code bits from these parallel binary channels are mapped to higher-order near-Gaussian distributed constellation symbols. At the receiver, the code bits are detected and decoded in a multistage fashion. The scheme is demonstrated on a simple instance of the linear Gaussian channel. Simulations show that the scheme achieves reliable communication at 1.2 dB away from the Shannon capacity using a moderate number of subchannels

Efficient balancing of q-ary sequences with parallel decoding

Abstract: Balancing of q-ary sequences, using a generalization of Knuth’s efficient parallel balancing scheme, is considered. It is shown that the new general scheme is as simple as the original binary scheme, which lends itself to parallel decoding of the balanced sequences