Recent content by Tybalt

Thanks. This is helpful.

Generally, spread spectrum is defined as using more spectrum (or bandwidth) than is needed to transmit a signal. But according to this definition, even TCP-IP would be a spreading scheme because it retransmits packets upon receiving a NACK. In OFDM, if you interleave data across the subcarriers...

That's the necessary condition of a proof that a "strictly" diagonally dominant matrix is invertible. The matrices I'm looking at are symmetric tri-diagonal.

This is how I constructed the matrix (M): I start with a complex nxn rank-n matrix (A) and remove a row to make (n-1)xn matrix (B). So B is an operator that maps n data symbols to (n-1) coded symbols, so obviously it has a zero eigenvalue. The inter-symbol interference matrix is M = (B^-1)B. The...

I'm trying to get an intuitive grasp of why an almost imperceptible change in the off-diagonal elements in a complex symmetric matrix causes it to change from being invertible to not being invertible. The diagonal elements are 1, and the sum of abs values of the off-diagonal elements in each row...