Abstract not found

Abstract not found

Cognitive radio is viewed as a novel approach for improving the utilization of a precious natural resource: the radio electromagnetic spectrum. The cognitive radio, built on a software-defined radio, is defined as an intelligent wireless communication system that is aware of its environment

This paper presents a simple two-branch transmit diversity scheme. Using two transmit antennas and one receive antenna the scheme provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas. It is also shown that the scheme may easily be generalized to two transmit antennas and w receive antennas to provide a diversity order of 2w. The new scheme does not require any bandwidth expansion any feedback from the receiver to the transmitter and its computation complexity is similar to MRRC.

Abstract. This paper is motivated by the need for fundamental understanding of ultimate limits of bandwidth efficient delivery of higher bit-rates in digital wireless communications and to also begin to look into how these limits might be approached. We examine exploitation of multi-element array

lecs.cs.ucla.edu As new fabrication and integration technologies reduce the cost and size of micro-sensors and wireless interfaces, it becomes feasible to deploy densely distributed wireless networks of sensors and actuators. These systems promise to revolutionize biological, earth

The performance of Ultrawideband (UWB) communications systems is determined by the propagation channels they operate in. This paper gives an overview of UWB channels and their impact on system design. The emphasis lies on (i) multiple antenna systems and (ii) body-area networks. We discuss

for high data rate wireless communication. The encoding/decoding complexity of these codes is comparable to trellis codes employed in practice over Gaussian channels. The codes constructed here provide the best tradeoff between data rate, diversity advantage, and trellis complexity. Simulation results

Abstract: Viterbi algorithm is employed in wireless communication to decode the Convolution codes; those codes are used in every robust digital communication systems. Such decoders are complex & dissipate large amount of power. Thus the paper presents the design of an Adaptive Viterbi Decoder

their performance. It is shown that using multiple transmit antennas and space–time block coding provides remarkable performance at the expense of almost no extra processing. Index Terms — Diversity, multipath channels, multiple antennas, space–time codes, wireless communication. I.