Efficient Power Allocation for Decentralized Distributed Space-Time Block Coding

Distributed space-time block coding (Dis-STBC) achieves diversity through cooperative transmission among geographically dispersed nodes. Several decentralized Dis-STBC schemes have been proposed to implement code-assignment at the relays without control signaling. Among the proposed power allocation strategies for decentralized Dis-STBC, the constant-power strategy is decentralized but inefficient; the near-optimal strategy requires some type of control signaling. In this paper, we propose a sub-optimal, decentralized power allocation strategy for decentralized Dis-STBC. In the proposed strategy, the power used by each relay is equal to the power used by source divided by the number of columns in the underlying STBC matrix. The outage analyses and simulations illustrate the power-efficiency advantage of the proposed strategy over the constant-power strategy.