TABLE OF CONTENTS The diversity gain achievable with multiple antenna systems can be obtained also with a MISO or a SIMO system. The unique feature of real MIMO systems is their capability of increasing the information rate for a given bandwidth and total transmit power. In this section we consider the performance of MIMO systems, in terms of average BER and mutual information, for different MIMO configurations. We will then assess the resilience of MIMO systems to interference and channel estimation errors.
We compare now the performance of MIMO systems in terms of average BER and mutual information, for different coding strategies, namely MinBER/ZF, MinBER/MMSE and MaxINF for different MIMO configurations. As an example, we considered multipath Rayleigh fading channels. Each channel is FIR of order L = 4 and the paths are statistically independent complex Gaussian random variables, with zero mean and unit variance. The average BER and information rate (IR), averaged over 100 independent channel realizations, are reported in Figures 6.9 and 6.10, respectively.
It is interesting to observe that the BER improves by increasing the number of antennas, but not as much as in the case analyzed in Chapter 5, where the transmitter had no channel knowledge. This...
