Cable Data
Two snapshots of received cable channel data streams and two channel models extracted from these original streams are provided. The cable data sequences (data 1 and data 2) have 64K complex-valued samples each, and the channels (channel 1 and channel 2) are modelled by 128 complex-valued taps. Such data are sampled at twice per symbol and the carrier frequency has been mixed close to 0 Hz; note that, there is some residual FM on the carrier.
The code below uses the channel model to find a perfect fractionally spaced equalizer (FSE), which can then be used to equalize the received sequence. The equalizer output eye diagram is plotted in blocks, since the residual FM phase causes a rotation of the constellation in time.
clear
load chan2;
HH=convmtx(C,128);
H=HH(1:2:size(HH,1),:);
tau=zeros(size(H,1),1);
tau(64)=1;
f=H\tau;
load data2;
y=conv(f,data);
plot(y(2:2:1000),'.');
title('Eye diagram of equalized cable data');