32-tap equalizer with 64-tap undermodeled channel and BPSK source

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3.3 32-tap equalizer with 64-tap undermodeled channel and BPSK source

Again consider the communications system in Figure 1 with an i.i.d. BPSK source, the (undermodeled) 64-tap channel impulse response shown in Figure 6, and a 32-tap FSE (N_f=32).

**Figure 6:** Impulse response of simulated 64-tap channel
$\begin{figure} \begin{center} \epsfxsize=2in \epsfbox{tchan.eps} \end{center} \end{figure}$

Since the equalizer has length larger than 2, the cost contours are not plotted. However, a simulation of 20,000 iterations with $\mu=2\times10^{-4}$ was performed, and the squared-error history is shown in Figure 7.

**Figure 7:** Comparison of error history for SE-CMA and CMA 2-2 (BPSK, 32-tap undermodeled channel, 15 dB SNR)
$\begin{figure} \begin{center} \epsfxsize=2in \epsfbox{ex4b.eps} \end{center} \end{figure}$

As shown, SE-CMA once again attains a lower error than CMA 2-2.

Andrew Grant Klein
8/12/1998