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

Improved transport capacity of the hexagonal lattice network with broadcast via network coding

The capacity of a wireless lattice network with local interference is studied. In particular, the transport capacity under a multiple unicast trac pattern is studied for a network of nodes placed on the hexagonal lattice. The communication model is that local interference allows reliable broadcast to all neighbors, but that simultaneous transmissions from multiple neighbors lead to a collision. If broadcast is not exploited and only point-to-point transmissions are used, the normalized transport capacity was previously shown to be between 1/3 and 2/5. In this work it is demonstrated that by exploiting broadcast the normalized transport capacity of the hexagonal lattice is at least 3/7