13 research outputs found
Minimum BER Precoding in 1-Bit Massive MIMO Systems
1-bit digital-to-analog (DACs) and analog-to-digital converters (ADCs) are
gaining more interest in massive MIMO systems for economical and computational
efficiency. We present a new precoding technique to mitigate the
inter-user-interference (IUI) and the channel distortions in a 1-bit downlink
MUMISO system with QPSK symbols. The transmit signal vector is optimized taking
into account the 1-bit quantization. We develop a sort of mapping based on a
look-up table (LUT) between the input signal and the transmit signal. The LUT
is updated for each channel realization. Simulation results show a significant
gain in terms of the uncoded bit-error-ratio (BER) compared to the existing
linear precoding techniques.Comment: Presented in IEEE SAM 2016, 10th-13th July 2016, Rio De Janeiro,
Brazi
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
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
Massive MIMO Downlink 1-Bit Precoding with Linear Programming for PSK Signaling
Quantized massive multiple-input-multiple-output (MIMO) systems are gaining
more interest due to their power efficiency. We present a new precoding
technique to mitigate the multi-user interference and the quantization
distortions in a downlink multi-user (MU) multiple-input-single-output (MISO)
system with 1-bit quantization at the transmitter. This work is restricted to
PSK modulation schemes. The transmit signal vector is optimized for every
desired received vector taking into account the 1-bit quantization. The
optimization is based on maximizing the safety margin to the decision
thresholds of the PSK modulation. Simulation results show a significant gain in
terms of the uncoded bit-error-ratio (BER) compared to the existing linear
precoding techniques.Comment: Submitted to SPAWC 201
Reconsidering Linear Transmit Signal Processing in 1-Bit Quantized Multi-User MISO Systems
In this contribution, we investigate a coarsely quantized Multi-User
(MU)-Multiple Input Single Output (MISO) downlink communication system, where
we assume 1-Bit Digital-to-Analog Converters (DACs) at the Base Station (BS)
antennas. First, we analyze the achievable sum rate lower-bound using the
Bussgang decomposition. In the presence of the non-linear quanization, our
analysis indicates the potential merit of reconsidering traditional signal
processing techniques in coarsely quantized systems, i.e., reconsidering
transmit covariance matrices whose rank is equal to the rank of the channel.
Furthermore, in the second part of this paper, we propose a linear precoder
design which achieves the predicted increase in performance compared with a
state of the art linear precoder design. Moreover, our linear signal processing
algorithm allows for higher-order modulation schemes to be employed
Quantized Constant Envelope Precoding with PSK and QAM Signaling
Coarsely quantized massive Multiple-Input Multiple-Output (MIMO) systems are
gaining more interest due to their power efficiency. We present a new precoding
technique to mitigate the Multi-User Interference (MUI) and the quantization
distortions in a downlink Multi-User (MU) MIMO system with coarsely Quantized
Constant Envelope (QCE) signals at the transmitter. The transmit signal vector
is optimized for every desired received vector taking into account the QCE
constraint. The optimization is based on maximizing the safety margin to the
decision thresholds of the receiver constellation modulation. Simulation
results show a significant gain in terms of the uncoded Bit Error Ratio (BER)
compared to the existing linear precoding techniques