A guide to the physical and mathematical-statistical approaches to personal and mobile wireless communication networks
Wireless Networks Technologies offers an authoritative account of several current and modern wireless networks and the corresponding novel technologies and techniques. The text explores the main aspects of the "physical layer" of the technology. The authorsânoted experts on the topicâexamine the well-known networks (from 2-G to 3-G) in a historical perspective. They also illuminate the "physical layer" of networks while presenting polarization diversity analysis and positioning of any subscriber located in areas of service both for land-to-land and land-to-atmosphere communication links.
The book includes clear descriptions of planning techniques for different integrated femto/pico/micro/macrocell deployments. The authors also examine new technologies of time and frequency dispersy and multiple-input and multiple-output (MIMO) modern network design in space and time domains. In addition, the text contains a discussion of a MIMO network based on multi-beam adaptive antennas. This important book:
Provides an examination of current and modern wireless networks
Describes various techniques of signal data capacity and spectral efficiency based on the universal stochastic approach
Explains how usage of MIMO systems with adaptive multi-beam antennas increase the grade of service and quality of service of modern networks beyond 4-G
Provides comparative analysis of depolarization effects and the corresponding path loss factor for rural, mixed residential, suburban, and urban land areas
Written for students and instructors as well as designers and engineers of wireless communications systems, Wireless Networks Technologies offers a combination of physical and mathematical-statistical approaches to predict operational parameters of land-to-land and land-to-atmosphere personal and mobile wireless communication networks.
Scanning the existing literature published during the recent two decades and related to the description of the wireless multiple access technologies, we notice that there are a lot of excellent works (see, for example, Refs. [1â22]), in which the multichannel, multiuser, and multicarrier accesses were described in detail for cellular and noncellular networks before and beyond third (3G) generation. However, all these works mostly described the corresponding techniques and technologies via a prism of additive white Gaussian noise (AWGN) and less via a prism of multiplicative noise that depend on fading phenomena, fast and slow, usually occurring in the wireless networks: terrestrial, atmospheric, and ionospheric [21, 22]. In other words, most of the excellent books had ignored the multiplicative noise caused by fading phenomena, which, as was shown in [21, 22], plays the main role in degradation of operational characteristics of any wireless network, such as grade of service (GoS), dealing with service of a lot of subscribers located in areas of service with a dense layout of users and quality of service (QoS), dealing with information data parameters sent and received by individual subscriber, such as the capacity, spectral efficiency, and bit error rate (BER) of data stream passing any wireless and wired communication link.
Thus, in [1â20], the authors dealt mostly with classical AWGN channels or channels with the interuser interference (IUI). As was shown there, the âresponseâ of such channels is not timeâ or frequency varied, that is, such propagation channels were not time or/and frequency dispersive. In [21, 22] the authors described the main features of the multiplicative noise caused by slow and fast fading that occur in terrestrial, atmospheric, and ionospheric wireless communication links and networks. As was shown in [21, 22], the aspects of fading are very important for predicting the multiplicative noise in various radio channels, terrestrial, atmospheric, and ionospheric, for the purpose of increasing the efficiency of landâland, landâaircraft, and landâsatellite communication networks. The proposed approaches were then extended for description of multimedia and optical communications based on stochastic, and other statistical, models [23â27] and on usage of special nonstandard matrices [28, 29].
Thus, in land communication channels, due to multiple scattering, diffraction, and scattering or diffuse reflection, the channel becomes frequency selective. If one of the antennas of the subscriber, or of the base station, is moving, the channel becomes both a timeâ and frequencyâdispersive channel. As a result, the radio signals traveling along different paths of varying lengths cause significant deviations in signal strength (in volts) or power (in watts) at the receiver. This interference picture is not changed with time and can be repeated in each phase of a radio communication link between the base station (BS) and the stationary subscriber. As for a dynamic channel, when either the subscriber antenna is in motion or the objects surrounding the stationary antennas move, the spatial variations of the resultant signal at the receiver can be seen as temporal variations, as the receiver moves through the multipath field (i.e. through the interference picture of the field strength). In such a dynamic multipath channel, a signal fading at the mobile receiver occurs in the time domain. This temporal fading relates to a shift in frequency radiated by the stationary transmitter. In fact, the time variations or dynamic changes of the propagation path lengths are related to the Doppler shift, denoted by
, which is caused by the relative movements of the stationary BS and/or the moving subscriber (MS). As was defined in [21, 22], the total bandwidth due to Doppler shift is
. In the timeâvaried or dynamic channel, for any real time
there is no repetition of the interference picture during the crossing of different field patterns by the MS at each discrete time of his movements. Thus, in Table 1.1, some characteristic parameters, such as introduced above, Doppler shi...
