Coordinated Multi-Point transmission with quantized and delayed feedback

Jaramillo-Ramírez, Daniel; Kountouris, Marios; Hardouin, Eric

doi:10.1109/glocom.2012.6503474

Cited by 9 publications

(11 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We can now use these expressions when composing first and second moments of Z cs in (23). As a result, we obtain…”

Section: Cs Methodsmentioning

confidence: 99%

“…The performance degradation due to feedback errors is presented in [20] while [21] shows that it is possible to design efficient codebooks even under imperfect feedback system. Furthermore, mechanisms to mitigate negative impact of feedback errors and delay are proposed in [22] while achievable rate analysis for JT CoMP under imperfect feedback is presented in [23,24]. 2.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance Analysis of Hierarchically Combined Practical Beamforming Methods

Haile

Hämäläinen

2015

Wireless Pers Commun

View full text Add to dashboard Cite

In literature various limited-feedback beamforming methods applied in co-located and distributed antenna systems have been proposed for enhancing wireless link spectral efficiency and reliability. We focus on practical limited-feedback methods and introduce a hierarchical feedback structure, whereby co-located/distributed transmit antennas are organized into two or more groups. To facilitate robust and flexible use of channel state information we apply independent feedback to antenna groups and between the groups. This structure provides additional implementation flexibility under practical constraints, particularly for coordinated multipoint (CoMP) systems. For the presented methods with hierarchical control structure, we compute closed-form expressions for the signal-to-noise power ratio gain, the fading figure and the average bit-error-probability. Although hierarchical structure leads in some cases to suboptimal methods, results show that performance loss against upper bound given by transmitter equal gain combining is negligible even when number of feedback bits is small. Thus, it is concluded that the hierarchical feedback that is robust against errors can be effectively used when antennas form natural groups like in e.g. CoMP transmission.

show abstract

“…We can now use these expressions when composing first and second moments of Z cs in (23). As a result, we obtain…”

Section: Cs Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Hierarchically Combined Practical Beamforming Methods

Haile

Hämäläinen

2015

Wireless Pers Commun

View full text Add to dashboard Cite

show abstract

“…The results are first given for the case of perfect CSI, and then under QD-CSI with and without OCI. In the homogeneous scenario (equal pathloss, no OCI), closed-form throughput expressions are derived in [8].…”

Section: Throughput Analysismentioning

confidence: 99%

“…The average rate is also upper bounded R SUJT ≤ log 2 (1 + P Nt MC MC i=1 γ u,i ). 2) QD-CSI, no OCI: Following derivations in [8], the received SNR under quantized and delayed CSI including pathloss is approximately given by…”

Section: Throughput Analysismentioning

confidence: 99%

“…[6] presents analysis on downlink CoMP with delayed feedback, while [7] includes quantized and delayed feedback (QD-CSI) and focuses on the issue of bit partitioning. Finally in [8], CBF and JT are investigated under both quantized and delayed CSI. However, in most previous work, a homogeneous scenario is considered, in which unequal pathloss from different BSs is known and compensated using power control.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Coordinated Multi-Point transmission with imperfect channel knowledge and other-cell interference

Jaramillo-Ramírez

Kountouris

Hardouin

2012

2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC)

Self Cite

View full text Add to dashboard Cite

Coordinated Multi-Point (CoMP) transmission is a promising technique for LTE-Advanced systems, especially due to the enhanced throughput performance of cell edge users. In this paper, we investigate joint transmission (JT) and coordinated beamforming (CBF) with quantized and delayed feedback, and we derive ergodic rate and outage probability expressions assuming large-scale fading (pathloss), small-scale Rayleigh fading, and other-cell interference (OCI). Furthermore, we employ a moment matching technique that approximates the distributions of the received desired and interference signals with Gamma distributions as a means to facilitate analysis and simulation. The performance of CoMP transmission is quantified and compared with non-cooperative transmission, and operating regions in which CoMP gains are more pronounced are provided. The versatility of the proposed approximate framework enables us to identify key system parameters, such as feedback resolution, pathloss, and transmit SNR for which CoMP becomes a judicious choice of transmission strategy.

show abstract

A novel quantized time‐domain compressed feedback scheme in coordinated multipoint LTE‐advanced systems

Wang

Lin

2014

Trans. Emerging Tel. Tech.

View full text Add to dashboard Cite

Coordinated Multi-Point technique has attracted much attention for its promising potential on improving spectral efficiency. However, in frequency division duplexing systems, significant channel state information (CSI) mismatch and huge feedback overhead greatly limit its performance. Within state of the art feedback schemes in which channel matrix are fed back over subcarriers, the feedback overhead is too large, and the achieved network gain is also limited. In this paper, we exploit the channel sparsity in time-domain and propose an quantized time-domain compressed feedback (QTDCF) scheme. For the sake of performance evaluation, two conventional feedback schemes are compared with our scheme. Rate gap between rate with perfect CSI and actual rate with erroneous CSI is used as the performance evaluation metric. A theoretic upper bound on the rate gaps, with respect to the total feedback overhead, is also derived for our scheme. Furthermore, considering the asymmetry characteristic of the global channel, an optimal bit allocation strategy among all cooperating cells is designed for our proposed QTDCF scheme. The proposed strategy is based on the branching and bounding theory with integer constraints on bits allocated for quantizing each channel coefficient over subcarriers or channel taps. Finally, simulation results show that our scheme can significantly reduce the feedback overhead and greatly improve the CSI reconstruction quality compared with existing feedback schemes.

show abstract

Coordinated Multi-Point transmission with quantized and delayed feedback

Cited by 9 publications

References 11 publications

Performance Analysis of Hierarchically Combined Practical Beamforming Methods

Performance Analysis of Hierarchically Combined Practical Beamforming Methods

Coordinated Multi-Point transmission with imperfect channel knowledge and other-cell interference

A novel quantized time‐domain compressed feedback scheme in coordinated multipoint LTE‐advanced systems

Contact Info

Product

Resources

About