Combined Frequency and Spatial Domains Power Distribution for MIMO-OFDM Transmission

Abstract

In this paper, we propose to adapt simultaneously the transmit power both in the spatial and frequency domains using a heuristic expression of the bit error rate (BER) for each subcarrier and transmit antenna. The proposed method consists of grouping a certain number of subcarriers and performing local power adaptation in each subcarrier group and transmit antenna. The subcarrier grouping is performed in such a way that equalizes the average channel condition of each subcarrier group. The grouping and the local power adaptation allow us to take advantage of the channel variations and to reduce the computational complexity of the proposed power distribution scheme. With the simplicity of the heuristic BER expression, we can obtain a closed form expression of the transmit power to be allocated. Simulation results show significant performance gain in term of BER compared to the equal power distribution.

Importance sampling techniques for estimating the bit error rate in digital communication systems

“…. , Z n g, where Z i follows a normal distribution with mean 0 and an unknown variance 2 " . In component (II), we receive the input signal X ¼ fX 1 , X 2 , .…”

“…To our knowledge, all existing papers on the estimation of BER using IS address the first issue. For general articles discussing the first issue, the reader can consult Jeruchim [8], Wang and Bhargava [16], Wang and Lu [17], Smith [14], Chen [4], Lee [10], Yoon et al [18], Roh and Rao [12], Chen et al [5], Chen et al [6], Chang and Oh [3], and Bocquet et al [2].…”