A new approach for designing linear dispersion space-time codes

In theory, multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations with low encoding and decoding complexity. In previous investigations, linear dispersion space-time block codes were proposed that can handle any configuration of transmit and receive antennas. This scheme transmits sub-streams of data in linear combinations over space and time and the codes are designed to optimize the mutual information between the transmitted and received signals with low complexity decoding. In this paper we focus on the capacity of a multiple antenna system in the presence of LD codes and extract the conditions (or characteristics) that LD codes must have to reach the capacity. Then considering these conditions, we introduce a new method to generate LD codes.