7,522 research outputs found
Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems
The ever-growing need for high data rate, bandwidthefficiency, reliability, less complexity and less power consumptionin our communication systems is on the increase.Modern techniques have to be developed and put in place tomeet these requirements. Research has shown, that compared toconventional Single input Single output (SISO) systems, MultipleinputSingle output (MISO), and Multiple-input multiple-output(MIMO) can actually increase the data rate of a communicationsystem, without actually requiring more transmit power orbandwidth. This paper aims at the investigation of the existingchannel estimation techniques. Based on the pilot arrangement,the block type and comb type are compared, employing theLeast Square estimation (L.S) and Minimum Mean SquaredError (MMSE) estimators. Pilots occupy bandwidth, minimizingthe number of pilots used to estimate the channel, in orderto allow for more bandwidth utilization for data transmission,without compromising the accuracy of the estimates is takeninto consideration. Various channel interpolation techniques andpilot-data insertion ratio are investigated, simulated and compared,to determine the best performance technique with lesscomplexity and minimum power consumption. As performancemeasures, the Mean squared error (MSE) and Bit error rate(BER) as a function of Signal to noise power ratio (SNR) ofthe different channel estimation techniques are plotted, in orderto identify the technique with the most optimal performance.The complexity and energy efficiency of the techniques are alsoinvestigated. The system modelling and simulations are carriedout using Matlab simulation package. The MIMO gives theoptimum performance, followed by the MISO and SISO. Thisis as a result of the diversity and multiplexing gain experiencedin the multiple antenna techniques using the STBC
Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems
AbstractâThe ever-growing need for high data rate, bandwidth
efficiency, reliability, less complexity and less power
consumption in our communication systems is on the increase.
Modern techniques have to be developed and put in place to meet
these requirements. Research has shown, that compared to conventional
Single Input Single Output (SISO) systems, Multiple-
Input Single Output (MISO), and Multiple-Input Multiple-
Output (MIMO) can actually increase the data rate of a communication
system, without actually requiring more transmit power
or bandwidth. This paper aims at the investigation of the existing
channel estimation techniques. Based on the pilot arrangement,
the block type and comb type are compared, employing the
Least Square estimation (L.S) and Minimum Mean Squared
Error (MMSE) estimators. Pilots occupy bandwidth, minimizing
the number of pilots used to estimate the channel, in order
to allow for more bandwidth utilization for data transmission,
without compromising the accuracy of the estimates is taken
into consideration. Various channel interpolation techniques and
pilot-data insertion ratio are investigated, simulated and compared,
to determine the best performance technique with less
complexity and minimum power consumption. As performance
measures, the Mean Squared Error (MSE) and Bit Error Rate
(BER) as a function of Signal to Noise power Ratio (SNR) of
the different channel estimation techniques are plotted, in order
to identify the technique with the most optimal performance.
The complexity and energy efficiency of the techniques are also
investigated. The system modelling and simulations are carried
out using Matlab simulation package. The MIMO gives the
optimum performance, followed by the MISO and SISO. This
is as a result of the diversity and multiplexing gain experienced
in the multiple antenna techniques using the STBC
Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems
The ever-growing need for high data rate, bandwidth
efficiency, reliability, less complexity and less power consumption
in our communication systems is on the increase.
Modern techniques have to be developed and put in place to
meet these requirements. Research has shown, that compared to
conventional Single input Single output (SISO) systems, Multipleinput
Single output (MISO), and Multiple-input multiple-output
(MIMO) can actually increase the data rate of a communication
system, without actually requiring more transmit power or
bandwidth. This paper aims at the investigation of the existing
channel estimation techniques. Based on the pilot arrangement,
the block type and comb type are compared, employing the
Least Square estimation (L.S) and Minimum Mean Squared
Error (MMSE) estimators. Pilots occupy bandwidth, minimizing
the number of pilots used to estimate the channel, in order
to allow for more bandwidth utilization for data transmission,
without compromising the accuracy of the estimates is taken
into consideration. Various channel interpolation techniques and
pilot-data insertion ratio are investigated, simulated and compared,
to determine the best performance technique with less
complexity and minimum power consumption. As performance
measures, the Mean squared error (MSE) and Bit error rate
(BER) as a function of Signal to noise power ratio (SNR) of
the different channel estimation techniques are plotted, in order
to identify the technique with the most optimal performance.
The complexity and energy efficiency of the techniques are also
investigated. The system modelling and simulations are carried
out using Matlab simulation package. The MIMO gives the
optimum performance, followed by the MISO and SISO. This
is as a result of the diversity and multiplexing gain experienced
in the multiple antenna techniques using the STBC
Robust massive MIMO Equilization for mmWave systems with low resolution ADCs
Leveraging the available millimeter wave spectrum will be important for 5G.
In this work, we investigate the performance of digital beamforming with low
resolution ADCs based on link level simulations including channel estimation,
MIMO equalization and channel decoding. We consider the recently agreed 3GPP NR
type 1 OFDM reference signals. The comparison shows sequential DCD outperforms
MMSE-based MIMO equalization both in terms of detection performance and
complexity. We also show that the DCD based algorithm is more robust to channel
estimation errors. In contrast to the common believe we also show that the
complexity of MMSE equalization for a massive MIMO system is not dominated by
the matrix inversion but by the computation of the Gram matrix.Comment: submitted to WCNC 2018 Workshop
Towards a Realistic Assessment of Multiple Antenna HCNs: Residual Additive Transceiver Hardware Impairments and Channel Aging
Given the critical dependence of broadcast channels by the accuracy of
channel state information at the transmitter (CSIT), we develop a general
downlink model with zero-forcing (ZF) precoding, applied in realistic
heterogeneous cellular systems with multiple antenna base stations (BSs).
Specifically, we take into consideration imperfect CSIT due to pilot
contamination, channel aging due to users relative movement, and unavoidable
residual additive transceiver hardware impairments (RATHIs). Assuming that the
BSs are Poisson distributed, the main contributions focus on the derivations of
the upper bound of the coverage probability and the achievable user rate for
this general model. We show that both the coverage probability and the user
rate are dependent on the imperfect CSIT and RATHIs. More concretely, we
quantify the resultant performance loss of the network due to these effects. We
depict that the uplink RATHIs have equal impact, but the downlink transmit BS
distortion has a greater impact than the receive hardware impairment of the
user. Thus, the transmit BS hardware should be of better quality than user's
receive hardware. Furthermore, we characterise both the coverage probability
and user rate in terms of the time variation of the channel. It is shown that
both of them decrease with increasing user mobility, but after a specific value
of the normalised Doppler shift, they increase again. Actually, the time
variation, following the Jakes autocorrelation function, mirrors this effect on
coverage probability and user rate. Finally, we consider space division
multiple access (SDMA), single user beamforming (SU-BF), and baseline
single-input single-output (SISO) transmission. A comparison among these
schemes reveals that the coverage by means of SU-BF outperforms SDMA in terms
of coverage.Comment: accepted in IEEE TV
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