ABSTRACT
During the last years, cooperative cellular systems have emerged as the next advancement toward the implementation of broadband wireless networks. However, the term “cooperation” can have diverse meanings in the context of wireless networks. Therefore, the purpose of this chapter is to identify the major cooperative strategies and to investigate the advantages of the cooperative cellular systems, which employ multicell joint processing with comparison to the conventional interference-limited cellular systems. More specifically, the architecture of cooperative cellular systems is described and analyzed and the channel coding schemeswhich fully exploit the cooperative architecture and achieve the optimal capacity are identified. In this context, the capacity performances of cooperative and conventional cellular systems are compared and the involved practical limitations are investigated.
During the last decades, wireless cellular systems have gone through an intensive evolutionary process, moving from analog voice streams to digital data services. As the demand for cost-efficient high-rate wireless services increases, the wireless network operators have to employ new wireless architectures to achieve higher data-rates. However, in spite of the evolution of the wireless cellular technologies, the increase in the system complexity becomes disproportional with respect to the provided capacity gain. Therefore, the research community as well as the industrial actors have begun a quest for alternative cellular architectures that have the ability to provide high spectral efficiencies. In this direction, cooperative wireless cellular architectures are gaining momentum as a dominant candidate for an alternative approach in wireless cellular networks.Cooperation in wireless networks can takemany forms, such as user terminal (UT) cooperation, base station (BS) cooperation and relaying.UT cooperation is theoretically possible but practically it involvesmany complications, because the UTs have to communicate either on a separate wireless frequency band or through the BS to exchange cooperative information. This fact results in a waste of spectrum and energy, which is very important in terms of battery life in mobile devices. Relaying can be beneficial, but it either consumes the resources of relaying UTs or requires the installation of additional transponders by the network operator.
