Communication technology and system design (Foreword)

Abstract

Communication system design is a rapidly growing technology. Recent advancement in this area played an important role in changing the human life more comfortable, to a great extent. Widespread use of wireless communication in turn demands efficient and affordable system design procedures, security, reliability and service diversity. This special issue is focused in the system design aspects of communication systems. Efficient modulation scheme, channel modeling, power allocation, security and hardware design aspects are the major area addressed. Below each of the paper is briefly introduced. Recent advancements in wireless system design resulted in widespread use of MIMO (Multiple Input Multiple Output) scheme. MIMO systems uses transmit diversity technique which results in high throughput with increased channel capacity. Space time block codes have proved its efficiency in MIMO systems, as the coding scheme. This is significant since the available spectral bandwidth, any advancement in improved capacity in turn provide high data rate. In conventional MIMO techniques, FFT (Fast Fourier Transform) is used as the modulation scheme which split the data into various sub bands. In the paper Wimax (IEEE 802.16 m) system based on space time block code and discrete multiwavelet transform, Vidhya Lavanya R. and Madheswaran M. takes a different approach by replacing the FFT by multiwavelet transforms. The improvement obtained is