Spatial multiplexing over correlated MIMO channels with a closed-form precoder

Akhtar, Jabran; Gesbert, David

doi:10.1109/twc.2005.853915

Cited by 32 publications

(21 citation statements)

References 19 publications

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“…Observe that with K = 0, γ k,l = Mρ k,l and the matrix becomes scale identical to the one presented in [12].…”

Section: ) Phase Optimizationmentioning

confidence: 89%

“…If a constant phase shift, or an exponential correlation model, is applied for the transmit correlation matrix then the solution provided by (33) will hold for all symbols [12] as long as K is small. For larger values of K, Hlos will dominate and the single phase shift it introduces can be canceled out for all symbols by selecting φi = −θ, i = 2, ..., N .…”

Section: ) Phase Optimizationmentioning

confidence: 99%

“…A high K factor with precoding makes the slope of the curve steeper as the fading is virtually non-existing. Further simulation results for transmit correlation cases may be found in [11], [12]. …”

Section: Simulationsmentioning

confidence: 99%

“…A closed-form solution for transmit correlation only, avoiding the need of any numerical optimization was presented in [11], [12]. The precoder is found in a closed-form as the solution to a linear equation parametrized as a function of the transmit correlation coefficient.…”

Section: Introductionmentioning

confidence: 99%

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Linear closed-form precoding of MIMO multiplexing systems in the presence of transmit correlation and ricean channel

Akhtar

Gesbert

Hjørungnes

IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.

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Abstract-This paper presents a closed-form linear precoder for a MIMO spatial multiplexing (SM) system in the presence of transmit correlation and a Ricean component. Existing SM (V-BLAST and similar schemes), based upon channel matrix inversion, rely on the linear independence of antenna channel responses for stream separation and suffer considerably from high levels of fading correlation and/or dominating ill-conditioned line-of-sight channel components. We propose a simple algorithm that adjusts the transmitted constellation through power weighting and phase shifts that can be interpreted in some extreme case as a higher order constellation design scheme. We obtain a rate-preserving MIMO multiplexing scheme that can operate smoothly at any degree of transmit correlation and any type of LOS channel component.

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“…Observe that with K = 0, γ k,l = Mρ k,l and the matrix becomes scale identical to the one presented in [12].…”

Section: ) Phase Optimizationmentioning

confidence: 89%

Section: ) Phase Optimizationmentioning

confidence: 99%

Section: Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Linear closed-form precoding of MIMO multiplexing systems in the presence of transmit correlation and ricean channel

Akhtar

Gesbert

Hjørungnes

IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.

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“…Among those, there has been a growing interest in transmitter schemes that can exploit low-rate long-term statistical channel state information in the form of antenna correlation coefficients. So far, emphasis has been on designing precoders for space-time block coded (STBC) [1] signals or spatially multiplexed streams that are adjusted based on the knowledge of the transmit correlation only while the receiving antennas are uncorrelated [2], [3], [4], [5]. These techniques are well suited to downlink situation where an elevated access point (situated above the surrounding clutter) transmits to a subscriber placed in a rich scattering environment.…”

Section: Introductionmentioning

confidence: 99%

Minimum exact SER precoding of orthogonal space-time block codes for correlated MIMO channels

Hjørungnes¹,

Gesbert²

IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.

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Abstract-A memoryless precoder is designed for orthogonal spacetime block codes for multiple-input multiple-output channels exhibiting joint transmit-receive correlation. Unlike most previous similar work which concentrate on transmit correlation only and pair-wise error probability (PEP) metrics, the precoder is designed to minimize the exact symbol error rate as function of the channel correlation coefficients, which are fed back to the transmitter, and the correlation may or may not follow the so-called Kronecker structure. The proposed method can handle general propagation settings including those arising form a cooperative macro-diversity (multi-base) scenario. We present two algorithms. This first is suboptimal, but provide a simple closed-form precoder that handles the case of uncorrelated transmitters, correlated receivers. The second is a fast-converging numerical optimization which covers the general case. The results show the SER based precoder has small gains over the PEP based precoder for moderate signal to noise ratios (SNR). Several properties of the minimum SER precoder are given. I. INTRODUCTIONIn the area of efficient communications over non-reciprocal MIMO channels, recent research has demonstrated the value of feeding back to the transmitter information about channel state observed at the receiver. Among those, there has been a growing interest in transmitter schemes that can exploit low-rate long-term statistical channel state information in the form of antenna correlation coefficients. So far, emphasis has been on designing precoders for space-time block . These techniques are well suited to downlink situation where an elevated access point (situated above the surrounding clutter) transmits to a subscriber placed in a rich scattering environment. Although simple models exist for the joint transmit receiver correlation based on the well known Kronecker structure [1], the accuracy of these models has recently been questioned in the literature based on measurement campaigns [6]. Therefore, there is interest in investigating the precoding of orthogonal space-time coded (OSTBC) signals for MIMO channels that do not necessarily follow the Kronecker structure.Methods have been proposed previously in the field of precoder design based on correlation knowledge on the transmitter side. For instance, an upper bound of the PEP is minimized in [2] for transmitonly correlation, and for full channel correlation in [7], [8]. In [9], the exact SER expressions were derived for when there is no receiver correlation and maximum ratio combining is used at the receiver. A bound of the exact error probability was used as the optimization criterion in [9]. The no receiver correlation assumption might be an unrealistic channel model for example in uplink communications, where the access point (receiver) is equipped with several receiver antennas and where the direction of arrival has a small spread at the receiver antennas. In [10], exact SER expressions were found

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Constellation constrained multiuser multiple‐input multiple‐output for high capacity and error performance over correlated fading channels

Al-Hussaibi

Ali

2014

Wireless Communications

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Channels' correlation has direct impact to degrade the capacity and reliability of multiple‐input multiple‐output (MIMO) systems considerably. In this paper, new signal constellation designs are investigated to mitigate fading correlation and maximize the capacity and error performance of multiuser MIMO (MU‐MIMO) over correlated channels, which is a major research challenge. Two methods are studied in a novel constellation constrained MU‐MIMO approach, namely, unequal power allocation and rotated constellation. Based on principles of maximizing the minimum Euclidean distance (dmin) of composite received signals, users' data can be recovered using maximum likelihood joint detection irrespective of correlation values. Compared with the identical constellation scenario in conventional MU‐MIMO, it is shown that constellation rearrangement of transmitted signals has direct impact to resolve the detection ambiguity when the channel difference is not sufficient, particularly in moderate to high correlations. Extensive analysis and simulation results demonstrate the superiority of proposed technique to capture most of the promised gains of multiantenna systems and application for future wireless communications. Copyright © 2014 John Wiley & Sons, Ltd.

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Spatial multiplexing over correlated MIMO channels with a closed-form precoder

Cited by 32 publications

References 19 publications

Linear closed-form precoding of MIMO multiplexing systems in the presence of transmit correlation and ricean channel

Linear closed-form precoding of MIMO multiplexing systems in the presence of transmit correlation and ricean channel

Minimum exact SER precoding of orthogonal space-time block codes for correlated MIMO channels

Constellation constrained multiuser multiple‐input multiple‐output for high capacity and error performance over correlated fading channels

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