Performance of Block Space-Time Code in Wireless Channel Dynamics

Won Mee Jang,Jong Hak Jung

doi:10.4236/ijcns.2009.26050

Abstract

In this work, we observe the behavior of block space-time code in wireless channel dynamics. The block space-time code is optimally constructed in slow fading. The block code in quasistatic fading channels provides affordable complexity in design and construction. Our results show that the performance of the block space-time code may not be as good as conventionally convolutional coding with serial transmission for some channel features. As channel approaches fast fading, a coded single antenna scheme can collect as much diversity as desired by correctly choosing the free distance of code. The results also point to the need for robust space-time code in dynamic wireless fading channels. We expect that self-encoded spread spec-trum with block space-time code will provide a robust performance in dynamic wireless fading channels.

Highlights

Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas in order to provide diversity at the receiver as well as coding gain without sacrificing bandwidth [1,2]
As wireless Internet services are incorporated into mobile communications, space-time codes that are optimal for fast fading channels, high data rate and low bit error rate (BER) are required
We assume that the perfect channel state information is available at receive antennas in the following simulations

Summary

Introduction

Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas in order to provide diversity at the receiver as well as coding gain without sacrificing bandwidth [1,2]. Most optimal space-time codes have been developed in block code in slow fading channels [1,3,4,5,6,7]. Tight exponential upper bound is obtained on the decoding error probability of block codes transmitted over fully interleaved fading channels with perfect CSI at the receiver [10]. Some space-time codes have been developed for fast fading channels under the assumption of low data rates and low signal-to-noise ratios [1]. We analyze and compare two different transmitter structures: the parallel transmitter that employs the block spacetime code and the serial signal transmitter Conventional channel code, such as convolutional code with a single transmit antenna, is used in the serial signal transmitter. Due to the inherent time diversity in SESS, we expect SESS block space-time code to maintain a robust performance in dynamic wireless fading channels

Block Space-Time Code

Conventional Serial Code

Simulation Results

Conclusions