PSAP (pre-selected artificial path) diversity system for indoor DS/CDMA

In a typical indoor environment such as in a building, delay spread tends to be small, which causes frequency non-selective fading. Therefore the resolvable paths at the receiver matched filter can not be obtained, and the effective path diversity can not be achieved. This paper proposes a pre-selected artificial path diversity method with multiple sector antennas consisting of delayed PN codes, which is an effective power scheme in such an indoor environment. In the proposed system, only pre-selected sector antennas transmit the signal to reduce signal redundancy, therefore the transmission power is used efficiently at the base station. As a result, better BER performance and the reduction of interference signals between the different channels by means of sector selection can be achieved.