SPATIAL DIVERSITY EQUALIZATION FOR MIMO OCEAN ACOUSTIC COMMUNICATION CHANNELS

The available bandwidth of ocean acoustic channels is inherently narro w that impedes high-transmission rate and makes it difficult for multi ple users to communicate simultaneously, To alleviate this problem, sp atial diversity antennas are used to increase the date rate, In this p aper, we employ the spatial diversity equalizers (SDE) to increase the effective channel bandwidth by minimizing the mean-square error (mse) . Although joint equalizers have been used in digital telephone subscr iber lines to suppress crosstalk, we apply the concept to ocean acoust ic channels and show that multiuser communication is possible despite the narrow-channel bandwidth. In addition, we will show that the advan tage of SDE is not because we use more taps, but because we collect th e data carried through various ocean paths. By applying the saddle poi nt integration method to multiinput multioutput (MIMO) channels, we co mpute the probability of error (PE) to show that a factor of 3-4 of ch annel reuse is possible.