Optimal placement of known symbols for slowly varying frequency-selective channels

Optimal Placement of Known Symbols for Nonergodic Broadcast Channels

Optimal placement of training for frequency-selective block-fading channels

The problem of placing training symbols optimally for orthogonal frequency-division multiplexing (OFDM) and single-carrier systems is considered. The channel is assumed to be quasi-static with a finite impulse response of length ( + 1) samples. Under the assumptions that neither the transmitter nor the receiver knows the channel, and that the receiver forms a minimum mean square error (MMSE) ch...

Optimal Pilot Placement for Time-Varying Channels

Two major training techniques for wireless channels are time division multiplexed (TDM) training and superimposed training. For the TDM schemes with regular periodic placements (RPP), the closedform expression for the steady-state minimum mean square error (MMSE) of channel estimate is obtained as a function of placement for Gauss-Markov flat fading channels. We then show that, among all period...

Detection with embedded known symbols: optimal symbol placement and equalization

Optimal embedding of known symbols for OFDM

The problem of placing known symbols optimally for OFDM is considered. The channel is assumed to be quasi-static with a finite impulse response. Under the assumption that neither the transmitter and receiver know the channel, we optimize the training by maximizing a lower bound of the mutual information. It is shown that the lower bound is maximized by placing the known symbols periodically. Op...