| 1. |
- Kanters, Noud, et al.
(författare)
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A Supervised Learning Framework for Joint Estimation of Angles-of-Arrival and Number of Sources
- 2022
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 10, s. 112086-112099
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Tidskriftsartikel (refereegranskat)abstract
- Machine learning is a promising technique for angle-of-arrival (AOA) estimation of waves impinging a sensor array. However, the majority of the methods proposed so far only consider a known, fixed number of impinging waves, i.e., a fixed number of sources (NOS). This paper proposes a machine-learning-based estimator designed for the case when the NOS is variable and hence unknown a priori. The proposed estimator comprises a framework of single-label classifiers. Each classifier predicts if waves are present within certain randomly selected segments of the array's field of view (FOV), resulting from discretising the FOV with a certain (FOV) resolution. The classifiers' predictions are combined into a probabilistic angle spectrum, whereupon the NOS and the AOAs are estimated jointly by applying a probability threshold whose optimal level is learned from data. The estimator's performance is assessed using a new performance metric: the joint AOA estimation success rate. Numerical simulations show that for low SNR (-10 dB), a low FOV resolution (2°) yields a higher success rate than a high resolution (1°), whereas the opposite applies for mid (0 dB) and high (10 dB) SNRs. In nearly all simulations, except one at low SNR and a high FOV resolution, the proposed estimator outperforms the MUSIC algorithm if the maximum allowed AOA estimation error is approximately equal to (or larger than) the FOV resolution.
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| 2. |
- Kanters, Noud, et al.
(författare)
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Channel Estimation Errors and Their Impact on Irregular Array Performance in Massive MIMO
- 2022
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Ingår i: 2022 International Symposium on Antennas and Propagation, ISAP 2022. ; , s. 509-510
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Konferensbidrag (refereegranskat)abstract
- This paper considers the impact of imperfect channel state information (CSI) on the array antenna layout design in massive multiple-input multiple-output applications. The analysis is based on channel estimation errors resulting from the least squares estimation algorithm in pure line-of-sight channels. We show that signal to interference-plus-noise ratio gains traditionally anticipated with irregular layouts, as compared to regular ones under the assumption of perfect CSI, vanish in case of CSI imperfections for the considered scenario.
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| 3. |
- Kanters, Noud, et al.
(författare)
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Stochastic array antenna figures-of-merit for quality-of-service-enhanced massive MIMO
- 2024
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Ingår i: Electronics Letters. - : WILEY. - 0013-5194 .- 1350-911X. ; 60:2
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows that the signal-to-interference-plus-noise ratio (SINR) at a base station (BS) equipped with an arbitrary physical array antenna can be expressed as a function of two fundamental, stochastic figure of merits (FoMs): (I) the instantaneous effective gain (IEG) and (II) the beamforming-channel correlation (BCC). This result is achieved by applying a novel channel normalization approach using a reference array to preserve effects induced by the embedded element patterns of physical antenna elements. It is shown that both FoMs provide essential insights for quality-of-service (QoS)-based array antenna design by investigating their statistics for BSs applying full-digital (FD) zero forcing (ZF) beamforming. Various array designs are evaluated, and it is shown that arrays with higher IEGs and a reduced probability of low BCCs can increase the ergodic sum rate and reduce the need for scheduling. This paper shows that the signal-to-interference-plus-noise ratio at a base station equipped with an arbitrary physical array antenna can be expressed as a function of two fundamental figures-of-merit: (I) the instantaneous effective gain (IEG), and (II) the beamforming-channel correlation (BCC). Various array designs were evaluated and it is shown that arrays with higher IEGs and a reduced probability of low BCCs can increase the ergodic sum rate and reduce the need for scheduling.image
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