Chapter 8
Throughput Performance Comparisons
In this chapter1 we take a closer look at Worldwide Inter-operability for Microwave Access (WiMAX) and High-Speed Downlink Packet Access (HSDPA), two successful cellular systems that are being operated currently in many countries. As researchers claim to be able to design a physical layer very close to the Shannon bound, we believe that it is now the time to check the truly achievable performance of these systems. Therefore, we have measured the physical-layer throughput of WiMAX and HSDPA in various realistic environments (urban and mountainous) with high-quality equipment and different antenna configurations. We furthermore compare the measured throughput with the Shannon bound and many other related bounds, reflecting design as well as implementation aspects.
8.1 Introduction
In 1948, Claude Shannon provided us with a clear channel capacity bound for point-to-point connections [7]. This bound was extended independently in the mid 1990s by Gerry Foschini and Mike Gans [1], as well as by Emre Telatar [8], to the case of multiple transmit and receive antennas; in short, Multiple-Input Multiple-Output (MIMO). It is this bound that we refer to and compare our throughput results with. It is this bound that coding experts compare with their turbo codes, as well as with their iterative receivers. Note, however, that this bound is a single-user bound even if it supports several transmit and receive antennas. Considering multiple users and/or ...
