Optimal Power Allocation and Power Control for VBLAST Systems with M-ary Modulations
Journal
IET Communications
Journal Volume
4
Journal Issue
6
Pages
956-966
Date Issued
2010-05
Author(s)
Abstract
In this study, the authors propose the optimal power allocation scheme that minimises the symbol error probability (SER) of vertical Bell Laboratories layered space-time (VBLAST) systems using M-ary modulations. The essence of the power allocation is to intentionally cause different received power from each layer at the receiver. By judiciously allocating the transmitting power to the layers, the performance of the successive interference cancelation at the receiver can be significantly improved. The exact SER of the VBLAST systems with non-uniform power allocation is analysed for the Rayleigh fading case. The SER is minimised to determine the optimal power allocation pattern for the VBLAST systems with M-ary modulations. Simulations show that our SER analysis is accurate and the proposed power allocation scheme significantly improves the performance of the VBLAST systems in fast fading environments by 3.5-4 dB. The work is applied to the power control of VBLAST systems in slow fading environments. Significant SNR gains of 8.5-10 dB are observed in the numerical experiments. It is also observed that the proposed optimal power allocation scheme can effectively reduce the SER variation among the layers. © 2010 The Institution of Engineering and Technology.
SDGs
Other Subjects
Fast fading environments; M-ary modulation; Nonuniform; Numerical experiments; Optimal power allocation; Power allocations; Received power; Slow fading; SNR gains; Successive interference cancelations; Symbol error probability; Transmitting power; V-BLAST; Vertical bell laboratories layered space-time; Modulation; Optimization; Power control; Probability; Rayleigh fading; Space time adaptive processing; Beamforming
Type
journal article