Joint transmitter and receiver design for MIMO channel shortening

The problem of joint transmitter and receiver design for multi-input multi-output (MIMO) channel shortening for frequency- selective fading channel is addressed. A frequency domain approach is followed which is equivalent to infinite length time-domain channel shortening equalizers (TEQ). A practical joint space and frequency waterfilling algorithm is also provided for optimum transmit power loading. It is demonstrated that the finite length TEQ suffers from a flooring effect on the compression ratio performance, whereas the proposed method overcomes this disadvantage. The noise amplification and the compression performance of the proposed joint tranceiver method is found to be better than both finite and infinite length receiver-only designs, with a gain of order of 3dB for a 2x2 MIMO channel.