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Joint Beamforming and Scheduling for a MIMO Downlink with Random Arrivals Mari Kobayashi

by Telecomunicacions Catalunya
"... Abstract—We study a number of downlink signaling strategies under perfect and non-perfect channel state information at the transmitter (CSIT) for the case of random packet arrivals. Under this setting, the relevant fairness criterion is the stabilization of all buffer queues which guarantees a bound ..."
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Abstract—We study a number of downlink signaling strategies under perfect and non-perfect channel state information at the transmitter (CSIT) for the case of random packet arrivals. Under this setting, the relevant fairness criterion is the stabilization of all buffer queues which guarantees a

Joint beamforming and scheduling for a multiantenna downlink with imperfect transmitter channel knowledge

by Mari Kobayashi - IEEE J. Select. Areas Commun , 2007
"... We consider the downlink of a wireless system where the base-station has M ≥ 1 antennas and K user terminals have one antenna each. We study the weighted rate sum maximization in the case of non-perfect Channel State Information at the Transmitter (CSIT). Some relevant downlink optimization problems ..."
Abstract - Cited by 22 (4 self) - Add to MetaCart
We consider the downlink of a wireless system where the base-station has M ≥ 1 antennas and K user terminals have one antenna each. We study the weighted rate sum maximization in the case of non-perfect Channel State Information at the Transmitter (CSIT). Some relevant downlink optimization

Spatial CSIT Allocation Policies for Network MIMO Channels

by Paul De Kerret, David Gesbert
"... In this work1, we study the problem of the optimal dissemination of channel state information (CSI) among K spatially distributed transmitters (TXs) jointly cooperating to serve K receivers (RXs). One of the particularities of this work lies in the fact that the CSI is distributed in the sense that ..."
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that each TX obtains its own estimate of the global multi-user MIMO channel with no further exchange of information being allowed between the TXs. Although this is well suited to model the cooperation between non-colocated TXs, e.g., in cellular Coordinated Multipoint (CoMP) schemes, this type of setting

Settling conjectures on the collapse of degrees of freedom under finite precision csit

by Arash Gholami Davoodi, Syed A. Jafar, Abstract—a Conjecture Made Lapidoth - in Proceedings of Globecom , 2014
"... states that the degrees of freedom (DoF) of a two user broadcast channel, where the transmitter is equipped with 2 antennas and each user is equipped with 1 antenna, must collapse under finite precision channel state information at the transmitter (CSIT). That this conjecture, which predates interfe ..."
Abstract - Cited by 1 (1 self) - Add to MetaCart
of K/2. However, while Cadambe and Jafar do so in the optimistic direction, showing that K/2 is optimal under perfect CSIT, here we close the gap in the pessimistic direction, showing that 1 DoF is optimal under finite precision CSIT. I.

Quantized vs. analog feedback for the MIMO downlink: a comparison between zero-forcing based achievable rates

by Giuseppe Caire , Nihar Jindal , Mari Kobayashi , Niranjay Ravindran - in Information Theory, 2007. ISIT 2007. IEEE International Symposium on , 2007
"... Abstract-We consider a MIMO fading broadcast channel and compare the achievable ergodic rates when the channel state information at the transmitter is provided by "analog" noisy feedback or by quantized (digital) feedback. The superiority of digital feedback is shown, with perfect or impe ..."
Abstract - Cited by 3 (1 self) - Add to MetaCart
-rate C and the zero-forcing sum-rate R ZF are equal to M log P/N 0 + O(1). On the contrary, under non-perfect CSIT the rate sum may behave in a radically different way; for example, if there is perfect CSIR and no CSIT when H has i.i.d. Gaussian entries, the sum rate is equal to log P/N 0 + O(1) [1] B

Cross-Layer Design for Single-Cell OFDMA systems with Heterogeneous QoS and Partial CSIT

by Charilaos C. Zarakovitis, Qiang Ni, Dionysios Skordoulis
"... Abstract — This paper proposes a novel cross-layer scheduling scheme for a single-cell orthogonal frequency division multiple access (OFDMA) wireless system with partial channel state information (CSI) at transmitter (CSIT) and heterogeneous user delay requirements. Previous research efforts on OFDM ..."
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on OFDMA resource allocation are typically based on the availability of perfect CSI or imperfect CSI but with small error variance. Either case consists to typify a non tangible system as the potential facts of channel feedback delay or large channel estimation errors have not been considered. Thus

Aligned image sets under channel uncertainty: Settling a conjecture by lapidoth, shamai and wigger on the collapse of degrees of freedom under finite precision csit,” arXiv preprint arXiv:1403.1541

by Arash Gholami Davoodi, Syed A. Jafar
"... A conjecture made by Lapidoth, Shamai and Wigger at Allerton 2005 (also an open problem presented at ITA 2006) states that the degrees of freedom (DoF) of a two user broadcast channel, where the transmitter is equipped with 2 antennas and each user is equipped with 1 antenna, must collapse under fin ..."
Abstract - Cited by 8 (1 self) - Add to MetaCart
uncertainty at the transmitter(s). In this work we prove that the conjecture is true in all non-degenerate settings (e.g., where the probability density function of unknown channel coefficients exists and is bounded). The DoF collapse even when perfect channel knowledge for one user is available

Analysis of multiple antenna systems with finite rate feedback using high resolution quantization theory,” submitted to IEEE Trans. on Signal Processing,

by Jun Zheng , Ethan Duni , Fellow, IEEE Bhaskar D Rao , 2005
"... Abstract This paper considers the development of a general framework for the analysis of transmit beamforming methods in multiple antenna systems with finite-rate feedback. Inspired by the results of classical high resolution quantization theory, the problem of finite-rate quantized communication s ..."
Abstract - Cited by 13 (9 self) - Add to MetaCart
system is formulated as a general fixed-rate vector quantization problem with side information available at the encoder (or the quantizer) but unavailable at the decoder. The framework of the quantization problem is sufficiently general to include quantization schemes with general non-mean square

The multip...

by Xiang Chen, Wei Miao, Yunzhou Li, Shidong Zhou, Jing Wang , 2010
"... In this paper, we study a MIMO fading broadcast channel where each receiver has perfect channel state information (CSI) while the channel state information at the transmitter (CSIT) is acquired by explicit channel feedback from each receiver through capacity-constrained feedback links. Two feedback ..."
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In this paper, we study a MIMO fading broadcast channel where each receiver has perfect channel state information (CSI) while the channel state information at the transmitter (CSIT) is acquired by explicit channel feedback from each receiver through capacity-constrained feedback links. Two feedback

Zero-Forcing DFE Transceiver Design Over Slowly Time-Varying MIMO Channels Using ST-GTD

by Chih-hao Liu, Student Member, Palghat P. Vaidyanathan
"... Abstract—This paper considers the optimization of transceivers with decision feedback equalizers (DFE) for slowly time-varying memoryless multi-input multi-output (MIMO) channels. The data vectors are grouped into space-time blocks (ST-blocks) for the spatial and temporal precoding to take advantage ..."
Abstract - Cited by 2 (0 self) - Add to MetaCart
advantage of the diversity offered by time-varying channels. The space-time generalized triangular decomposition (ST-GTD) is proposed for application in time-varying channels. Under the assumption that the instan-taneous channel state information at the transmitter (CSIT) and receiver (CSIR
Results 1 - 10 of 15