24.01.10: Signal Proc :: Channel Estimation - I, Maximum Likelihood Estimate
In Signal Processing and Communications, one often has to deal with unknown signals. For example, the wireless channel (air medium) distorts the transmitted signal in so many ways (multipath fading, ISI, etc.) that the receiver has to use its own methods to recover the signal. Generally, such signals are modeled as stochastic random processes and statistical methods are used to "demystify" the received waveform. The air medium can be considered to be a time-varying FIR filter and the receiver unit must estimate the properties of this wireless medium.Such techniques are called Channel Estimation methods.
I have begun a series of articles, in which I'll explain the various methods of channel estimation. In this post, I'll explain a method called as Maximum Likelihood Estimate. I give an example on how to estimate the mean and variance of the wireless channel. To start with, I consider a time-invariant () system. Later, we'll consider time-varying systems. This article involves so much math that HTML can't cope with it. I used LaTeX and converted it to pdf. You can download it here.
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Posted by: bdsatish Category: Signal Proc
