On the other hand, several MIMO configurations have been considered to compare performances in terms of channel capacity including electromagnetic parameters of the antenna, such as radiation patterns and mutual coupling. The Spatial Channel Model from 3 GPP has been used for the simulations. Higher capacity has been obtained in the configuration where the two antennas has been placed in parallel with a spacing of 0.4 wavelengths within a PDA, mainly due to the lower mutual coupling and thus to uncorrelation between MIMO subchannels. Moreover, the radiation pattern for both antennas has been measured and MIMO channel measurement have been carried our in an indoor environment, obtaining in average higher capacity in the case of the designed PIFAs. ACKNOWLEDGMENTThe authors wish to thank S.R.F. Moyano, from Dragados Industrial, especially to Mr. Alberto Martínez Ollero, for the support of this research work conducted as part of the PIDEA SMART project and partially funded by PROFIT FIT-330210 -2005-107

Multiple-input multiple-output (MIMO) technology constitutes a breakthrough in the design of wireless communications systems, and is already at the core of several wireless standards. Exploiting multipath scattering, MIMO techniques deliver significant performance enhancements in terms of data transmission rate and interference reduction. This 2007 book is a detailed introduction to the analysis and design of MIMO wireless systems. Beginning with an overview of MIMO technology, the authors then examine the fundamental capacity limits of MIMO systems. Transmitter design, including precoding and space-time coding, is then treated in depth, and the book closes with two chapters devoted to receiver design. Written by a team of leading experts, the book blends theoretical analysis with physical insights, and highlights a range of key design challenges. It can be used as a textbook for advanced courses on wireless communications, and will also appeal to researchers and practitioners working on MIMO wireless systems.

No abstract

We address the problem of designing jointly optimum linear precoder and decoder for a MIMO channel possibly with delay-spread, using a weighted minimum mean-squared error (MMSE) criterion subject to a transmit power constraint. We show that the optimum linear precoder and decoder diagonalize the MIMO channel into eigen subchannels, for any set of error weights. Furthermore, we derive the optimum linear precoder and decoder as functions of the error weights and consider specialized designs based on specific choices of error weights. We show how to obtain: 1) the maximum information rate design; 2) QoS-based design (we show how to achieve any set of relative SNRs across the subchannels); and 3) the (unweighted) MMSE and equal-error design for fixed rate systems.

No abstract