As commented in Chapter 9, it is certainly desirable to bring some quantification to the qualitative descriptions of modulation systems given in Chapter 9 and their possible differences when sent through an RFPA. It is clear that such quantification cannot be beneficially pursued using formal symbolic analysis, and computation in some form or another is required. Bridging the gaps between a CCDF plot, a PA behavioral model, and a regulatory specification in a quantitative manner is a task which still challenges CAD manufacturers. In what follows, we do not in any way attempt to compete with the still-emerging professional CAD simulation tools in this area. But it is on occasion useful to be able to negotiate the gaps, even if it is with a piece of string rather than a six-lane highway.

The CD-ROM accompaniment to this book contains a number of spreadsheets which are prefixed by a modulation system. Two specific cases (EDGE.ACP and OFDM.ACP) are set up to demonstrate how a passable spectrum can be obtained using the Excel FFT routine, which is part of the data analysis package. These spreadsheets also include some basic PA distortion models, which enable the effects of PA distortion to be observed as ACP on the spectra. Readers can easily add their own variations by using these spreadsheets as templates.

The .ACP spreadsheet template uses a 4096 data sample, which is taken at 10 samples per symbol. This represents a very short data burst, and in order to obtain a meaningful spectrum,...