The Optimization Of Multiple Antenna Broadband Wireless Communications

The Optimization of Multiple Antenna Broadband Wireless Communications

AbstractTHE OPTIMIZATION OF MULTIPLE ANTENNA BROADBANDWIRELESS COMMUNICATIONSA study of propagation, space-time coding and spatial envelope correlationin Multiple Input, Multiple Output radio systemsKeywordsMultiple Output Multiple Input (MIMO) ; Orthogonal Frequency-Division Multiplexing(OFDM); Space Time Block Coding (STBC); Diversity; Spatial Envelope Correlation;Indoor Channel Propagation; IEEE 802.11n, WiMAXThis work concentrates on the application of diversity techniques and space time block coding for futuremobile wireless communications.The initial system analysis employs a space-time coded OFDM transmitter over a multipath Rayleighchannel, and a receiver which uses a selection combining diversity technique. The performance of thiscombined scenario is characterised in terms of the bit error rate and throughput. A novel four elementQOSTBC scheme is introduced, it is created by reforming the detection matrix of the original QOSTBCscheme, for which an orthogonal channel matrix is derived. This results in a computationally less complexlinear decoding scheme as compared with the original QOSTBC. Space time coding schemes for three, fourand eight transmitters were also derived using a Hadamard matrix.The practical optimization of multi-antenna networks is studied for realistic indoor and mixed propagationscenarios. The starting point is a detailed analysis of the throughput and field strength distributions for acommercial dual band 802.11n MIMO radio operating indoors in a variety of line of sight and non-line ofsight scenarios. The physical model of the space is based on architectural schematics, and realisticpropagation data for the construction materials. The modelling is then extended and generalized to a multistorey indoor environment, and a large mixed site for indoor and outdoor channels based on the BradfordUniversity campus.The implications for the physical layer are also explored through the specification of antenna envelopecorrelation coefficients. Initially this is for an antenna module configuration with two independent antennasin close proximity. An operational method is proposed using the scattering parameters of the system andwhich incorporates the intrinsic power losses of the radiating elements. The method is extended to estimatethe envelope correlation coefficient for any two elements in a general (N,N) MIMO antenna array. Threeexamples are presented to validate this technique, and very close agreement is shown to exist between thismethod and the full electromagnetic analysis using the far field antenna radiation patterns.

The Optimization of Multiple Antenna Broadband Wireless Communications

Optimizing Wireless Communication Systems

In June 2000, GTEL (Wireless Telecommunications Research Group) at the F- eral University of Ceara ́ was founded by Professor Rodrigo Cavalcanti and his c- leagues with the mission of developing wireless communications technology and impact the development of the Brazilian telecommunications sector. From the start, this research effort has been supported by Ericsson Research providing a dynamic environment where academia and industry together can address timely and relevant research challenges. This book summarized much of the research output that has resulted from GTEL’s efforts. It provides a comprehensive treatment of the physical and multiple access layers in mobile communication systems describing different generations of systems but with a focus on 3G systems. The team of Professor C- alcanti has contributed scienti cally to the development of this eld and built up an impressive expertise. In the chapters that follow, they share their views and kno- edge on the underlying principles and technical trade-offs when designing the air interface of 3G systems. The complexity of 3G systems and the interaction between the physical and m- tiple access layers present a tremendous challenge when modeling, designing, and analyzing the mobile communication system. Herein, the authors tackle this pr- lem in an impressive manner. Their work is very much in line with the developments in 3GPP providing a deeper understanding of the evolution of 3G and also future enhancements.