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Codebook
About: Codebook is a research topic. Over the lifetime, 8492 publications have been published within this topic receiving 115995 citations.
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TL;DR: A new vector quantization method that generates codewords incrementally that works better than some recently published efficient algorithms such as Enhanced LBG for traditional tasks and can be used for new tasks that are insoluble using traditional methods.
52 citations
Patent•
20 Dec 2019TL;DR: In this paper, a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook construction method is proposed for constructing a hybrid HARQ codebook, which comprises receiving physical downlink control channels (PDCCHs) that convey respective DCI formats, wherein each DCI format includes a counter field and a slot offset field.
Abstract: A method of a user equipment (UE) for constructing a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook. The method comprises receiving physical downlink control channels (PDCCHs) that convey respective downlink control information (DCI) formats, wherein each DCI format includes a counter field and a slot offset field, receiving physical downlink data channels (PDSCHs) that convey data transport blocks, detecting the DCI formats configuring the received PDSCHs, determining locations for HARQ-ACK bits in a HARQ-ACK codebook based on a value of the slot offset field and a value of the counter field in each detected DCI format, determining a time unit for transmission of the HARQ-ACK codebook based on a value of the slot offset field in each detected DCI format, and transmitting the HARQ-ACK codebook.
51 citations
Patent•
07 Feb 2007TL;DR: In this article, beamforming is based on codewords of a polar-cap codebook which represents deviations in the channel with respect to codeword of a full-manifold codebook.
Abstract: Embodiments of a multiple-input multiple-output (MIMO) communication system and methods for beamforming using polar-cap codebooks are generally described herein. Other embodiments may be described and claimed. In some embodiments, beamforming is based on codewords of a polar-cap codebook which represents deviations in the channel with respect to codewords of a full-manifold codebook.
51 citations
08 Jun 2015
TL;DR: An effective codebook is designed, using a genetic algorithm that achieves a near-optimal array gain in all directions, and a low complexity channel estimation scheme is proposed that requires less signalling overhead and is effective with low-resolution phase shifters.
Abstract: Millimeter wave (mmWave) technologies can enable current mobile communication systems to achieve higher data rates. However, wireless channels at mmWave frequencies experience higher isotropic path loss. Therefore, employing a suitable beamforming algorithm is an indispensable element of any mmWave system. Traditional multiple-input multiple-output (MIMO) systems employ digital beamforming where each antenna element is equipped with one RF chain. In case of mmWave systems, however, the power consumption, signalling and hardware cost impose the designers to deploy analog or hybrid beamforming strategies. This paper addresses two key problems in beamforming for millimeter wave communication systems. First, an effective codebook is designed, using a genetic algorithm that achieves a near-optimal array gain in all directions. This RF codebook is shown to perform better compared to the state-of-the-art RF codebooks with fewer RF chains and lower resolution phase shifters. Secondly, a low complexity channel estimation scheme is proposed that requires less signalling overhead and is effective with low-resolution phase shifters. Finally, the performance of the proposed RF codebook and channel estimation scheme is thoroughly investigated in terms of spectral efficiency.
51 citations
01 Jul 2006
TL;DR: The results show that the mapping quality obtained with OVI-NG outperforms the original CCA, in terms of the trustworthiness, continuity, topographic function and topology preservation measures.
Abstract: A high-quality distance preserving output representation is provided to the neural gas (NG) network. The nonlinear mapping is determined concurrently along with the codebook vectors. The adaptation rule for codebook positions in the projection space minimizes a cost function that favors the trustworthy preservation of the local topology. The proposed visualization method, called OVI-NG, is an enhancement over curvilinear component analysis (CCA). The results show that the mapping quality obtained with OVI-NG outperforms the original CCA, in terms of the trustworthiness, continuity, topographic function and topology preservation measures.
51 citations