Multi-User MIMO Channel Emulator with Automatic Channel Sounding Feedback

Tran Thi Thao NGUYEN  Leonardo LANANTE  Yuhei NAGAO  Hiroshi OCHI  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E99-A   No.11   pp.1918-1927
Publication Date: 2016/11/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E99.A.1918
Type of Manuscript: Special Section PAPER (Special Section on Smart Multimedia & Communication Systems)
Category: VLSI Design Technology and CAD
Keyword: 
MIMO channel emulator,  FPGA implementation,  channel state information,  IEEE 802.11n/ac,  frequency selective fading,  

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Summary: 
Wireless channel emulators are used for the performance evaluation of wireless systems when actual wireless environment test is infeasible. The main contribution of this paper is the design of a MU-MIMO channel emulator capable of sending channel feedback automatically to the access point from the generated channel coefficients after the programmable time duration. This function is used for MU beamforming features of IEEE 802.11ac. The second contribution is the low complexity design of MIMO channel emulator with a single path implementation for all MIMO channel taps. A single path design allows all elements of the MIMO channel matrix to use only one Gaussian noise generator, Doppler filter, spatial correlation channel and Rician fading emulator to minimize the hardware complexity. In addition, single path implementation allows the addition of the feedback channel output with only a few additional non-sequential elements which would otherwise double in a parallel implementation. To demonstrate the functionality of our MU-MIMO channel emulator, we present actual hardware emulator results of MU-BF receive signal constellation on oscilloscope.