A Transmit Antenna Selection for MIMO Wireless Ad-Hoc Networks in Lossy Environment

Because of rapid channel attenuation in lossy environment, there is a severe packet drop loss problem in wireless ad hoc networks. Though MIMO (Multi-Input Multi-Output) technology can alleviate this effect greatly, it will result in higher transmission energy depletion as using more transmit antennas. Lots of schemes have been proposed to reduce such energy cost by transmit antenna selection. However, most of those only consider QoS requirements between neighbor nodes while ignoring QoS requirements for entire network. In this paper, we investigate an energy-efficient transmit antenna selection problem for many-to-one communications, while guaranteeing a certain packet drop loss ratio from any node to the sink. We prove that this problem (Transmit Antenna Selection Problem, TASP) is NP-hard. Thus, a greedy algorithm TASA (Transmit Antenna Selection Algorithm) is proposed to solve this problem. This paper also prove the correctness of the proposed algorithm and the time complexity of TASA algorithm is O(|E|+|V|-M_T), where |V| represents the number of nodes, |E| indicates the number of links and M_T is the number of transmit antennas on each node, respectively. Our numerical results show that in a 100 node network, TASA can reduce transmission energy cost by 44.3% on average.