Handbook of Smart Antennas for RFID Systems

CHAPTER 19

OPTIMUM POWER ALLOCATION IN MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEMS UNDER INDEPENDENT RAYLEIGH FADING

JEFFREY S. FU

Department of Electronic Engineering, Chang Gung University, Taoyuan, Taiwan, Republic of China

WEIXIAN LIU

School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore

NEMAI CHANDRA KARMAKAR

Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Victoria, Australia

19.1 INTRODUCTION

Appearing a few years ago, a series of information theory articles were published by members of Bell Laboratories. Multiple-input multiple-output (MIMO) systems have evolved quickly to both become one of the most popular topics among wireless communication researchers and reach a spot in today’s “hottest wireless technology” list. The MIMO systems, with antenna array at both transmitter and receiver sides, are able to increase spectral efficiency greatly using spatial diversity, which can be accomplished in a rich scattering channel environment [1,2]. The radio-frequency identification (RFID) system experiences such a rich scattering channel environment where multiple tags are to be read in warehouses, retail stores, manufacturing industries, and so on. Recent research has shown that high theoretical capacity is possible since data rates as high as 40 bits/s/Hz have been demonstrated in an indoor slow-fading environment [3].

Optimal power allocation plays an important role for a MIMO system to achieve maximum ...