This paper proposes a statistical-eigenmode space-division multiple-access (SE-SDMA) transmission for a two-user downlink system where two transmit antennas are equipped at the base station and each mobile user has on...
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ISBN:
(纸本)9781457720529
This paper proposes a statistical-eigenmode space-division multiple-access (SE-SDMA) transmission for a two-user downlink system where two transmit antennas are equipped at the base station and each mobile user has one receive antenna, assuming that only statistical channel state information (CSI) is available at the transmitter. By maximizing a lower bound of the ergodic signal-to-leakage-and-noise ratio, the proposed SE-SDMA approach selects two users with orthogonal principal statistical eigen-directions and transmits to each user along the corresponding eigenmode. We derive an exact expression of the ergodic achievable rate, and compare it with the zero-forcing beamforming (ZFBF) system exploiting instantaneous CSI. It is shown that SE-SDMA can achieve the maximum ergodic sum-rate of the two selected users, and provide significant user selection gain. Analytical and simulation results show that the rate gap between SE-SDMA and ZFBF with perfect CSI at the transmitter can tend to zero in highly correlated channels, which indicates that statistical precoding can be used instead of instantaneous precoding in certain environments.
Past studies on Cooperative Multi-Point (CoMP) Processing/Base Station Cooperation (BSC) technique have shown its potential for system capacity improvement. However, many of the previous studies ignore a fact that in ...
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ISBN:
(纸本)9781457713460
Past studies on Cooperative Multi-Point (CoMP) Processing/Base Station Cooperation (BSC) technique have shown its potential for system capacity improvement. However, many of the previous studies ignore a fact that in a network where multiple CoMP groups co-exist, the interference between CoMP groups would significantly decrease each of the CoMP groups' performance. To combat this Interference between CoMP groups, we propose a novel precoding technique - Maximum Eigenmode Transmission (MET) CoMP precoding, which is able to effectively combat such interference and achieves 90% better performance than the conventional method in a multi-group CoMP network.
Multi-user multiple input multiple output (MU-MIMO) systems can achieve high spectral efficiency for wireless communication. The design of optimal transmit precoding for max-sum-rate (MSR) MU-MIMO downlink transmissio...
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ISBN:
(纸本)9781457713460
Multi-user multiple input multiple output (MU-MIMO) systems can achieve high spectral efficiency for wireless communication. The design of optimal transmit precoding for max-sum-rate (MSR) MU-MIMO downlink transmission is a non-trivial problem. Recent research approached this problem by exploiting the relationship between max-sum-rate and the minimum-mean-squared-error (MMSE) and proposed several iterative schemes. Based on these research results, we propose enhanced iterative MSR algorithms for linear MU-MIMO precoding which improve the sum rate performance and reduce the computational complexity. The effectiveness of the proposed method is verified by numerical simulations.
This paper studies the downlink closed loop transmission in the 3G long term evolution (LTE) system. We propose a precoding matrix selection algorithm from a finite codebook. The precoding, antenna selection, adaptive...
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ISBN:
(纸本)9781424459353
This paper studies the downlink closed loop transmission in the 3G long term evolution (LTE) system. We propose a precoding matrix selection algorithm from a finite codebook. The precoding, antenna selection, adaptive modulation and coding (AMC) require the channel information fed back from receiver to optimize the system performance. We study the codebook design and precoding matrix selection in LTE system, particularly the single user (SU) in a fading channel scenario. As a comparison to precoding, the antenna subset selection is investigated. The link adaption based on the instantaneous signal-to-noise ratio is also studied. The proposed rank and link adaption algorithm select the precoding matrix and AMC that maximize the spectral efficiency under a certain frame error rate constraint.
Multibeam satellite communication (SatCom) with full or aggressive frequency re-use is one of the most promising candidates for next-generation high throughput satellite systems. However, frequency re-use creates inte...
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ISBN:
(纸本)9781509032556
Multibeam satellite communication (SatCom) with full or aggressive frequency re-use is one of the most promising candidates for next-generation high throughput satellite systems. However, frequency re-use creates interbeam interference which needs to be managed using multiuser precoding techniques in the forward link and multiuser detection techniques in the reverse link. This work considers the forward link of multibeam Sat-Com systems and proposes a novel zero-forcing (ZF) precoding technique that makes use of users' physical location and antenna radiation pattern available at the gateway. Contrary to conventional precoding techniques in multibeam SatCom systems, the proposed precoding technique does not require feedback from user terminals. Numerical results show that the proposed ZF precoder achieves higher ergodic capacity than the conventional ZF precoder. We provide a closed-form approximation for the ergodic capacity of the proposed ZF precoder under rain fading. We also provide a closed-form approximation for computing the moments of the rain fading attenuation which enables us to derive high and low signal-to-noise ratio (SNR) expressions of the ergodic capacity in closed-form. Furthermore, an upper bound on the ergodic capacity is obtained. Monte Carlo simulations are used to validate the accuracy of our analysis.
In the paper, we propose a novel transmit precoding named "nonlinear block multi-diagonalization (NL-BMD) precoding," composed of block multi-diagonalization and adjacent inter-user interference pre-cancella...
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ISBN:
(纸本)9781509032556
In the paper, we propose a novel transmit precoding named "nonlinear block multi-diagonalization (NL-BMD) precoding," composed of block multi-diagonalization and adjacent inter-user interference pre-cancellation, for multiuser MIMO downlink toward 5G. It is revealed through computer simulations that, the proposed NL-BMD precoding yields up to 77% performance improvement in average sum-rate throughput and enables large-capacity transmission regardless of the user configuration, compared with the conventional block diagonalization precoding.
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