Cooperative Communications: Hardware, Channel & PHY

5

Hardware Issues

5.1 Introductory Note

5.1.1 Chapter Contents

In the end, it is the hardware that facilitates as well as limits any implementation of cooperative relaying schemes. These limitations in hardware favor some implementations but also render a low-complexity implementation of some of the recently proposed cooperative protocols infeasible. As of 2009, however, there is very little material available on hardware issues explicitly pertaining to cooperative systems. We will hence treat in this chapter the following issues:

• analog hardware transceiver components and designs;
• digital hardware transceiver components and designs;
• complexity and cost comparisons of these architectures;
• complexity and power consumption of 3G UMTS voice/HSDPA relay;
• complexity and power consumption of LTE/WiMAX relay;
• available hardware demonstrators.

Note that, from a hardware point of view, a preferred way of distinguishing between architectures is to divide them into purely analog and digital architectures. Fortunately, there is a simple mapping of hardware architectures to protocol families of Table 1.2 and multiple access methods of Figure 1.17: All regenerative relaying protocols must be realized by a digital hardware architecture, and all transparent relaying protocols can be realized by either a digital or a purely analog hardware architecture. Furthermore, TDR must be realized by a digital hardware architecture and both FDR or DFR can be realized by either a digital or a purely analog ...