Performance and capacity analysis for downlink pico-cellular distributed antenna systems with transmit antenna selection

Distributed antenna systems (DAS) is considered to be a promising candidate for future mobile communications. Recent studies have shown that DAS can extend coverage, increase system capacity and reduced radiated power. In this paper, ergodic capacity of two transmission strategies: single transmit antenna selection (STAS) scheme and dual transmit antennas selection (DTAS) scheme is analyzed in downlink pico-cellular DAS, symbol error probability (SER) performances is investigated as well. The results show that compared with conventional cellular systems, the proposed pico-cellular DAS obviously improves capacity and reduces SER for the users near the cell boundary, moreover, the average capacity is improved more than 30% while saving more than 70% transmit power. Therefore, pico-cellular DAS architecture appears to be an effective solution to improve channel capacity in power-limited cellular systems.