| Communications Toolbox | |
The semianalytic technique works well for certain types of communication systems, but not for others. The semianalytic technique is applicable if a system has all of these characteristics:
Any effects of multipath fading, quantization, and amplifier nonlinearities must precede the effects of noise in the actual channel being modeled.
The receiver is perfectly synchronized with the carrier, and timing jitter is negligible. Because phase noise and timing jitter are slow processes, they reduce the applicability of the semianalytic technique to a communication system.
The noiseless simulation has no errors in the received signal constellation. Distortions from sources other than noise should be mild enough to keep each signal point in its correct decision region. If this is not the case, then the calculated BER will be too low. For instance, if the modeled system has a phase rotation that places the received signal points outside their proper decision regions, then the semianalytic technique is not suitable to predict system performance.
Furthermore, the semianalytic function assumes that the noise in the actual channel being modeled is Gaussian. For details on how to adapt the semianalytic technique for non-Gaussian noise, see the discussion of generalized exponential distributions in [3].
| | Performance Results via the Semianalytic Technique | Procedure for the Semianalytic Technique | |
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