Low complexity turbo space-time code for system with large number of antennas

We consider the design of a space-time code for a system with large number of antennas using a serial turbo code structure with a parity cheek code as the outer code under a quasistatic and independent Rayleigh fading environment. By studying the case with a large number of receive antennas, we have proven that interference between different transmit antennas vanishes as the number of receive antennas approaches infinity. The design of a code can then be largely simplified by dividing the antennas into groups, using a small space-time code on each group. An outer code is added to allow each information bit to fully utilize the full range of antenna diversity and to be benefited from all the space-time codes. Dividing the overall system into groups enables a trade off between complexity and performance. This scheme has been investigated for systems with 5 receive antennas and 2 or 4 transmit antennas. Simulation results showed that the system performance in terms of the frame error rate degrades only slightly when both the data rate and the number of transmit antennas are doubled while keeping the received energy per bit at the receiver constant