[...]... network is accessed by NI inputs and NO outputs In this context, the term channel is not limited to the physical transmission Wireless Communications over MIMO Channels Volker K¨ hn u  2006 John Wiley & Sons, Ltd 2 INTRODUCTION TO DIGITAL COMMUNICATIONS 1 1 2 2 channel NI NO Figure 1. 1 Principle of multiple access to a common channel medium, that is, the radio channel, but has a more general meaning and... error probabilities 1. 1 Basic System Model 1. 1 .1 Introduction Vector channels, or multiple-input multiple-output (MIMO) channels, represent a very general description for a wide range of applications They incorporate SISO (Single-Input Single-Output), MISO (Multiple-Input Single-Output) and SIMO (Single-Input MultipleOutput) channels as special cases Often, MIMO channels are only associated with multiple... transmission Here, delays of only around 10 ms are tolerable 8 INTRODUCTION TO DIGITAL COMMUNICATIONS Since the interleaver has to first be completely written before it can be read out, its size Lπ directly determines the delay t = Lπ · Ts 1. 2 Characteristics of Mobile Radio Channels 1. 2 .1 Equivalent Baseband Representation Wireless channels for mobile radio communications are challenging media that... consisting of Lrow rows and Lcol columns, and reading them row by row An example with Lrow = 3 and Lcol = 4 is shown in Figure 1. 7 The input sequence b[0], b [1] , b [11 ] develops into the following due to interleaving b[0], b[3], b[6], b[9], b [1] , b[4], b[7] b [10 ], b[2], b[5], b[8], b [11 ] It is recognized that there is a spacing between the originally successive symbols of LI = 4 This gap is called interleaving... 279 282 293 304 304 306 308 312 319 320 3 21 3 21 322 323 323 323 325 328 Appendix A Channel Models A .1 Equivalent Baseband Representation A.2 Typical Propagation Profiles for Outdoor Mobile Radio Channels A.3 Moment-Generating Function for Ricean Fading 329 329 330 3 31 5.4 5.5 Nonlinear Iterative Multiuser Detection 5.3 .1 Nonlinear Devices ... Global System for Mobile (GSM) Communications and Digital Cellular System (DCS )18 00 standards both combine Time division multiple access (TDMA) and FDMA In UMTS (Universal Mobile Telecommunications System) or IMT-2000 (International Mobile Communications) systems, CDMA is used in connection with TDMA and FDMA (Dahlman et al 19 98; Ojanper¨ and Prasad 19 98b; Toskala et al 19 98) While TDMA, FDMA, and a... Moreover, we will see in Section 3 that interleaving is also employed in concatenated coding schemes INTRODUCTION TO DIGITAL COMMUNICATIONS b[ ] 7 write ˜ b[ ] b[0] b[3] b[6] b[9] read b [1] b[4] b[7] b [10 ] b[2] b[5] b[8] b [11 ] Figure 1. 7 Structure of block interleaver of length Lπ = 12 Block interleaver There are several types of interleaving The simplest one is termed block interleaver, which divides... Section 1. 2 addresses the mobile radio channel with its statistical properties and the way of modeling it Some analysis concerning signal detection and the theoretical performance of linear schemes for different transmission channels are presented in Sections 1. 3 and 1. 4 Finally, Section 1. 5 explains the principle of diversity and delivers basic results for outage and ergodic error probabilities 1. 1 Basic... (Alamouti 19 98; Naguib et al 19 98; Seshadri and Winters 19 94; Tarokh et al 19 99a) and, therefore, enhance the link performance The link reliability can also be improved by beamforming, which enlarges the signal to noise ratio (SNR) Alternatively, several data streams can be multiplexed over spatially separated channels in order to multiply the data rate without increasing bandwidth (Foschini 19 96; Foschini... 6.4 .1 LD Description of Alamouti’s Scheme 6.4.2 LD Description of Multilayer Transmissions 6.4.3 LD Description of Beamforming 6.4.4 Optimizing Linear Dispersion Codes 6.4.5 Detection of Linear Dispersion Codes 6.5 Information Theoretic Analysis 6.5 .1 Uncorrelated MIMO Channels 6.5.2 Correlated MIMO Channels . class="bi x0 y0 w0 h0" alt=""