Compressive sensing methods are used in channel estimation when the channel is thread as sparse where there are zero points in the signal representation. I am in the beginning of the sparse signal processing and trying to understand how to model the sparse channel in the equation below.
Y(k)=H(k)X(k) === > Y(k) received signal in frequency domain
My questions are:
1-What is the presentation of sparse channel h in this equation? 2-How to define the dictionary matrix for sparse channel? 3-For sparse estimation do we need to insert pilot symbols into the transmitted data x(n)? 4-Do you have a reference which explains the sparse channel properties in OFDM systems?
I would appreciate if someone please help on this topic.