Diversity Order of Linear Equalizers for Block Transmission in Fading Channels

We address diversity order of linear equalization for block transmission in fading channels. It is known that zero padded (ZP) block transmission allows LE to achieve full multipath diversity present in frequency selective channels. We show here that, in a dual fashion, LE can achieve full Doppler-diversity in time-selective channels when guard bands are inserted in the transmit signal. For these transmission schemes we derive an upper bound for the orthogonal deficiency [1] of the effective channel matrix at the receiver to prove that LE can exploit full diversity present in the channel. We also analyze the performance of LE with linear precoded transmission in doubly selective channels and extend this proof to show that LE can also achieve maximal joint multipath-Doppler diversity offered by doubly selective channels.