2 × n 時空區塊碼之可適性功率分配

Abstract

In this paper, we explore the application of adaptive power allocation to 2 × nr space-time block code (STBC) systems, where nr specifies an arbitrary number of antennas at the receiver. We demonstrated how a fixed amount of transmit power allocated among the transmit antennas in different quantities can result in an improved bit error rate (BER) performance. Using a feed-back link between the transmitter and receiver, adaptive power allocation can also be used to improve the system capacity or minimize the transmit power of a system while satisfying a threshold BER equirement. Our method for allocating the transmit power is compared with the conventional power allocation method of water-filling and with a hypothetical capacity-constrained waterfilling method. The case of imperfect channel estimation at the receiver is also analyzed for its effects on the performance of adaptive power allocation.