Effects of correlated shadowing and multipath fading on OFDM systems with postdetection-combining-based macrodiversity

The performance of orthogonal frequency division multiplexing (OFDM) using postdetection-combining-based macrodiversity is analyzed on a shadowed multipath channel, and the effects of correlated shadowing are investigated. We show that the postdetection-combining-based macrodiversity provides larger performance gain than the selection-based one, especially for the channel characterized by random multipath parameters. It is also shown that the gain obtained by using the postdetection-combining-based macrodiversity is reduced more and more as the correlation among the macrodiversity ports increases. Even for the fully correlated shadowing situation, however, the postdetection-combining-based macrodiversity still provides a considerable gain compared with no diversity case.