Linear Precoding for High-K-Factor Channels Exploiting Channel Mean and Covariance Information

Oteri, O.; Yoon, Eunchul; Paulraj, A.

doi:10.1109/tvt.2007.899957

Cited by 9 publications

(14 citation statements)

References 10 publications

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“…The first term of the right-hand side denotes the channel mean or the line-of sight (LOS) component : In uncorrelated Rayleigh channels, [5] shows that random vector quantization (RVQ) is amenable to analysis and performs close to the optimal quantization. When channels are Rician fading, we will prove that channel directions are distributed only along some directions and then the RVQ scheme is not the quasioptimal scheme.…”

Section: System Descriptionmentioning

confidence: 99%

“…If the transmit and receive chains are properly calibrated such that reciprocity of the channel applies, the uplink and downlink will experience the same channel realization for a given time-frequency slot. Even in FDD systems, the channel statistics of the uplink and downlink are still remain related [5].…”

Section: A Statistical Channel Knowledge At the Transmittermentioning

confidence: 99%

“…Gamma M γ [5]. We define the norm of the inner product of these two unit vectors as the angle distance between these two unit vectors, and then the angle distance between the channel direction and the LOS component direction is express as:…”

Section: B the Direction Distribution Of Rician Channelmentioning

confidence: 99%

“…As the channel statistical information can be obtained at the transmitter with little or no feedback [4], [5], it is assumed that the transmitter knows users' channel statistic information. As channels here are uncorrelated, the channel statistic information refers to the channel mean which can be modeled as the LOS component of the Rician channel.…”

Section: Algorithm Descriptionmentioning

confidence: 99%

“…The channel model is uncorrelated Rician fading [5]. As the channel statistical information change slowly, and can in many cases be estimated directly at the transmitter from the reverse communication link (see in section III), we can assume that the base station (BS) has each user's channel statistic information.…”

Section: Introductionmentioning

confidence: 99%

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Limited Feedback Technique of MU-MISO System over Rician Fading Channels

Yang

Qiu

2009

2009 Pacific-Asia Conference on Circuits, Communications and Systems

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A new limited feedback scheme over Rician channels is proposed in multi-antenna multiuser downlink systems. By introducing angle distance distribution in the Rician channel, the scheme designs the quantization codebook which is closer to the channel direction for each user. Moreover, the proposed scheme can adapt the number of feedback bits to the channel condition without increasing the quantized error. The simulation results show that the proposed scheme outperforms Random Vector Quantization schemes both on increasing throughput and on decreasing feedback overhead in Rician channels.Keywords-multi-antenna multiuser downlink system; Rician channel; zero forcing beamforming; limited feedback; random vector quantization; quantized error

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Section: System Descriptionmentioning

confidence: 99%

Section: A Statistical Channel Knowledge At the Transmittermentioning

confidence: 99%

Section: B the Direction Distribution Of Rician Channelmentioning

confidence: 99%

Section: Algorithm Descriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Limited Feedback Technique of MU-MISO System over Rician Fading Channels

Yang

Qiu

2009

2009 Pacific-Asia Conference on Circuits, Communications and Systems

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Enhancing secrecy capacity of multi‐relay wiretap systems with partial channel state information

Long

Wang

et al. 2014

Int J Communication

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Distributed precoding has proven to be capable of enhancing the secrecy capacity of the multi-relay wiretap system. An iterative distributed precoding and channel state information (CSI) sharing scheme can be used to reduce the CSI overhead at each relay node. However, in practical applications, the CSI of each relay node cannot be perfectly known to themselves, especially that of the relay-eavesdropper channels. Thus, partial CSI for the relay-eavesdropper links is assumed, and the corresponding distributed precoding and CSI sharing schemes are investigated. Under the assumption that the average value of the relay-eavesdropper channel is known at each relay node, an extended iterative distributed precoding and CSI sharing scheme is proposed. Simulation results demonstrate that with the increase of the power ratio of the constant part to the random part of the relay-eavesdropper channels, the proposed scheme with partial CSI performs increasingly close to the one with perfect CSI in secrecy capacity. Figure 2. Secrecy capacity of the multi-relay system with M D 2.the Rician channel than with the Rayleigh channel. The proposed ITP with the average channel values performs better with the increase of K. The gap between the ITP schemes with perfect and partial CSI narrows with the increase of K, because the random parts of the R i -E channels become smaller.The secrecy capacity results are plotted in Figure 3 with M D 3. The observation from Figure 3 is similar to that from Figure 2. The difference between ITP with perfect and partial CSI is negligible as can be seen from Figure 3(a). The relationship among the ITP schemes with different CSI assumptions can be clearly observed from Figure 3(c). When K is small and the R i -E channels are Figure 3. Secrecy capacity of the multi-relay system with M D 3.almost unknown, the ITP w/ AV scheme has similar performance as that without the R i -E CSI. If K is larger than 10 dB, the gap between ITP with perfect and partial CSI is negligible.The results in Figures 2(c) and 3(c) demonstrate that the proposed ITP schemes with partial CSI is suited for the Rician channel with the average channel values available at the relay nodes. The power ratio K between the constant and random parts affects the performance of the proposed scheme. As shown in Figures 2(c) and 3(c), if K < 4 dB, namely, each relay node almost knows nothing about the related R i -E channel, the ITP w/AV scheme performs close to that without the eavesdropper information. On the other hand, if K > 10 dB, the proposed scheme with partial CSI is similar to that with perfect CSI.

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Precoding for multiple‐input multiple‐output systems with space–time block coding over correlated Rician fading channels

Dang

Rui

et al. 2014

IET Communications

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Linear Precoding for High-K-Factor Channels Exploiting Channel Mean and Covariance Information

Cited by 9 publications

References 10 publications

Limited Feedback Technique of MU-MISO System over Rician Fading Channels

Limited Feedback Technique of MU-MISO System over Rician Fading Channels

Enhancing secrecy capacity of multi‐relay wiretap systems with partial channel state information

Precoding for multiple‐input multiple‐output systems with space–time block coding over correlated Rician fading channels

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