tailieunhanh - Adaptive thu phát không dây P9

RBF-Equalized Adaptive Modulation Having considered the concepts of RBF-assisted channel equalization in Chapter 8, we are now ready to amalgamate these concepts with the AQAM philosophy detailed in Part I of the book. Although it is advantageous for the reader to consult Part I of the book, before delving into Part I1 dedicated to RBF-assisted arrangements, there is sufficient background information in this part of the book for the reader to be able to dispense with reading Part I. | Adaptive Wireless Tranceivers L. Hanzo . Wong . Yee Copyright 2002 John Wiley Sons Ltd ISBNs 0-470-84689-5 Hardback 0-470-84776-X Electronic Chapter RBF-Equalized Adaptive Modulation Having considered the concepts of RBF-assisted channel equalization in Chapter 8 we are now ready to amalgamate these concepts with the AQAM philosophy detailed in Part I of the book. Although it is advantageous for the reader to consult Part I of the book before delving into Part II dedicated to RBF-assisted arrangements there is sufficient background information in this part of the book for the reader to be able to dispense with reading Part I. Here we will commence by providing a brief introduction to the state-of-the-art in AQAM transmissions over both narrow-band as well as wide-band channels and then we will refer back to Part I of the book in more detail with the objective of establishing a link betwen the two parts. Based on the foundations of the previous chapter in this chapter the concept of RBF equalizers is extended to Burst-by-Burst BbB Adaptive QAM AQAM schemes. As discussed in Part I of the book BbB AQAM schemes employ a higher-order modulation mode in transmission bursts when the channel quality is favourable in order to increase the throughput and conversely a more robust but lower-order modulation mode is utilized in those transmission bursts where the instantaneous channel quality drops. The modem mode switching regime will be detailed in more depth during our further discourse. We will show that this RBF-AQAM scheme naturally lends itself to accurate channel quality estimation. We will provide an outline of our various assumptions and the description of the simulation model leading to our RBF-AQAM performance studies. This scheme is shown to give a significant improvement in terms of the mean BER and bits per symbol BPS performance compared to that of the individual fixed modulation modes. Let us now commence with a brief background on adaptive modulation in