Blind Channel Equalization for Fast Moving Terminals in Prioritized Spatial Multiplexing MIMO Systems
A prioritized spatial multiplexing scheme has recently been developed for the transmission of scalable video coded (SVC) video over MIMO systems. One unique feature of this scheme is its capability to channelize the sub-channels according to the importance of the individually transmitted data streams. We consider in this research a challenging task of providing high quality multimedia services over MIMO systems with fast moving terminals. With fast moving terminals many existing approaches for MIMO channel estimation and equalization cannot be applied as most of them rely on the help of periodic pilot signals. When the terminals are travelling in high speed, the undesired Doppler effects prevent the existing approaches from efficient use of pilot signals for channel estimation and equalization. Although existing blind channel estimation and equalization schemes are able to avoid the problems associated with pilot signals, these schemes cannot be directly adopted for the prioritized spatial multiplexing MIMO system for video streaming in which data streams under different modulations need to be transmitted through sub-channels. In this paper, we develop a blind constant modulus algorithm (CMA)-based channel equalization (CMACE) scheme to track the fast time-varying channel without the requirement of pilot signals. We show that the transmitted signal in each sub-channel can be modulated with different symbol constellation, and delivered at different rate according to their importance. Simulation results demonstrate that the proposed scheme is effective for channel equalization with fast moving terminal in the prioritized spatial multiplexing MIMO systems