Investigation of front-end requirements for MIMO-systems using downlink pre-distortion

Brühl, Lars; Degen, Christoph; Keusgen, Wilhelm; Rembold, Bernhard; Walke, Christoph M.

doi:10.1049/cp:20030300

Cited by 12 publications

(10 citation statements)

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“…Calibration requirements of a system using separate transmitters and receivers are investigated based on a scattering approach introduced in Reference [9]. The disparities introduced by different reflection factors at the transmitters and receivers in combination with antenna matching and/or mutual coupling can be made small …”

Section: Front-end Imperfectionsmentioning

confidence: 99%

“…One option of calibration tries to minimise the difference T BS À R BS directly by comparing the transmitter and receiver chain of each transceiver of the base station separately. If this difference equals 0, the estimated symbols of user k follow for ZF-based predistortion aŝ that needs to be compensated for at the mobile stations [9].…”

Section: Front-end Imperfectionsmentioning

confidence: 99%

“…In order to evaluate the necessary accuracy of reciprocity and to derive appropriate calibration techniques, a system model based on scattering matrices has been presented in Reference [9]. Therein, the influence of unequal transfer functions of transmitters and receivers, antenna mismatching and coupling was investigated.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of MIMO systems with respect to front‐end imperfections

Degen

Koch

Keusgen

et al. 2006

Trans Emerging Tel Tech

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In multiuser multiple-input multiple-output (MIMO) systems the performance of joint detection and joint predistortion techniques highly depends on the quality of radio-frequency (RF) components. Therefore, the focus of this paper is on front-end imperfections. We demonstrate the influence of erroneous calibration (which is essential for downlink predistortion), phase noise and nonlinear amplifiers. For all issues we elaborate on the different disturbances that arise, analyse the impact on symbol estimation and evaluate system performance in terms of coded bit error ratio (BER). A general result for all examined front-end imperfections is that their influence increases with the number of spatially multiplexed data streams culminating in unacceptable performance degradation in fully loaded systems. Moreover, Wiener-based detection and predistortion reduces the degradation due to front-end imperfections in low SNR regimes compared to zero forcing

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Section: Front-end Imperfectionsmentioning

confidence: 99%

Section: Front-end Imperfectionsmentioning

confidence: 99%

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Evaluation of MIMO systems with respect to front‐end imperfections

Degen

Koch

Keusgen

et al. 2006

Trans Emerging Tel Tech

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“…Even if assuming reasonably good antenna isolation in each device, there are always unavoidable frequency response (FR) mismatches between the transmitter (TX, containing, e.g., mixers, power amplifier and RF filtering) and receiver (RX, e.g., RF filtering, LNA, mixers, and lowpass filtering) chains implemented in the same transceiver, which, in turn, distort the reciprocal nature of the effective DL and UL channels. As shown in [5]- [10], if the CSIT at the BS is obtained by measuring the UL signals under transceiver non-reciprocity, inter-user interference (IUI) occurs at user equipment (UE) reception and thus causes severe performance degradation in TDD MU MIMO-OFDM DL transmission.…”

mentioning

confidence: 99%

“…In [5]- [8], direct offline hardware estimation-calibration is proposed. It provides a standard independent solution yet adds substantial implementation complexity and cost for each device.…”

mentioning

confidence: 99%

Efficient Estimation and Compensation of Transceiver Non-Reciprocity in Precoded TDD Multi-User MIMO-OFDM Systems

Zou

Raeesi

Valkama

2014

2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall)

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In this paper, we propose an efficient transceiver non-reciprocity estimation-compensation framework for precoded TDD multi-user MIMO-OFDM downlink transmission systems. General signal models are first developed to analyze the effects of transceiver non-reciprocity at both the base-station and user equipment sides. The analysis shows that transceiver nonreciprocity at the base-station causes inter-user interference and thus substantial performance degradation, while the impact of transceiver non-reciprocity at the user equipment side can be fairly easily handled with downlink detector processing. Next, an overthe-air (OTA) type pilot-based estimation algorithm is devised for efficient identification of base-station non-reciprocity parameters, which are then used in pre-compensating or precoding the multiuser data properly in the base-station. Compared to the existing work in the literature, the proposed approach does not require the use of feedback signaling or complicated channel matrix decomposition techniques for extracting the non-reciprocity parameters. The resulting link and system performance of the proposed estimation-compensation framework is then evaluated using extensive computer simulations in linear precoded TDD multiuser MIMO-OFDM system context. Based on the obtained results, the proposed estimation-compensation approach can provide a simple, practical and flexible solution to efficiently restore the channel reciprocity with reasonable calibration overhead.

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Mehrantennensysteme im Mobilfunk

Rembold

2015

Wellenausbreitung

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Investigation of front-end requirements for MIMO-systems using downlink pre-distortion

Cited by 12 publications

References 0 publications

Evaluation of MIMO systems with respect to front‐end imperfections

Evaluation of MIMO systems with respect to front‐end imperfections

Efficient Estimation and Compensation of Transceiver Non-Reciprocity in Precoded TDD Multi-User MIMO-OFDM Systems

Mehrantennensysteme im Mobilfunk

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