Rayleigh fading converts an exponential dependency of the bit error probability on the average received bit energy-to-noise ratio into an inverse linear one, yielding a very large performance loss. Diversity is one very effective remedy that exploits the principle of providing the receiver with multiple independently faded replicas of the same information bearing signal. This chapter concentrates on antenna diversity techniques, although the mathematical concepts will readily apply to other types of diversity as well. We first consider diversity systems consisting of a single transmit antenna and multiple receiver antennas. Various diversity combining techniques are treated including selective combining, maximal ratio combining, equal gain combining, switched combining, and differential detection with postdetection equal gain combining. Later, optimum combining is considered which is useful for combating both fading and co-channel interference. The chapter then goes on to treat the case of multiple transmit antennas, where an antenna array is used for beam forming. Finally, the chapter wraps up with the Alamouti transmit diversity scheme, where there are multiple transmit antennas and either a single or multiple receive antennas.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
Bitte loggen Sie sich ein, um Zugang zu diesem Inhalt zu erhalten
Sie möchten Zugang zu diesem Inhalt erhalten? Dann informieren Sie sich jetzt über unsere Produkte:
- Multi-antenna Techniques
Gordon L. Stüber
- Springer New York
- Chapter 6