656 research outputs found
1-Bit Massive MIMO Downlink Based on Constructive Interference
In this paper, we focus on the multiuser massive multiple-input single-output
(MISO) downlink with low-cost 1-bit digital-to-analog converters (DACs) for PSK
modulation, and propose a low-complexity refinement process that is applicable
to any existing 1-bit precoding approaches based on the constructive
interference (CI) formulation. With the decomposition of the signals along the
detection thresholds, we first formulate a simple symbol-scaling method as the
performance metric. The low-complexity refinement approach is subsequently
introduced, where we aim to improve the introduced symbol-scaling performance
metric by modifying the transmit signal on one antenna at a time. Numerical
results validate the effectiveness of the proposed refinement method on
existing approaches for massive MIMO with 1-bit DACs, and the performance
improvements are most significant for the low-complexity quantized zero-forcing
(ZF) method.Comment: 5 pages, EUSIPCO 201
MMSE precoder for massive MIMO using 1-bit quantization
We propose a novel linear minimum-mean-squared-error (MMSE) precoder design
for a downlink (DL) massive multiple-input-multiple-output (MIMO) scenario. For
economical and computational efficiency reasons low resolution 1-bit
digital-to-analog (DAC) and analog-to-digital (ADC) converters are used. This
comes at the cost of performance gain that can be recovered by the large number
of antennas deployed at the base station (BS) and an appropiate precoder design
to mitigate the distortions due to the coarse quantization. The proposed
precoder takes the quantization non-linearities into account and is split into
a digital precoder and an analog precoder. We formulate the two-stage precoding
problem such that the MSE of the users is minimized under the 1-bit constraint.
In the simulations, we compare the new optimized precoding scheme with
previously proposed linear precoders in terms of uncoded bit error ratio (BER).Comment: Presented in ICASSP 2016, 20-25 March 2016, Shanghai, Chin
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