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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.


Papers
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Journal ArticleDOI
TL;DR: This paper addresses a hierarchical decode-and-forward (HDF) strategy in the wireless two-way relay channel (2-WRC) that uses a Hierarchical eXclusive Code (HXC) that allows full decoding of the hierarchical symbols at the relay.
Abstract: This paper addresses a hierarchical decode-and-forward (HDF) strategy in the wireless two-way relay channel (2-WRC). This strategy uses a Hierarchical eXclusive Code (HXC) that allows full decoding of the hierarchical symbols at the relay. The HXC represents two data sources only through the exclusive law and requires side information on the complementary data at the destination (which naturally holds for the 2-WRC). The HDF strategy has the advantage over classical medium-access control (MAC) stage relaying with joint decoding in that its rate region extends beyond the classical MAC region. We present a layered design of the HXC codebook, which uses an arbitrary outer state-of-the-art capacity-approaching code [e.g., low density parity check (LDPC)] and an inner layer with an exclusive symbol alphabet. We provide basic theorems, showing that this scheme forms an HXC, and we also evaluate its alphabet-constrained rate regions. The rate regions depend on the relative channel phase parameters. Some channel rotation leads to catastrophic violation of the exclusive law. However, these values appear only in a limited range of phases and have only a mild impact on the mean capacity for some component symbol constellations.

58 citations

Patent
19 Nov 1991
TL;DR: In this paper, a variable rate vector quantization method employs a tree structured codebook and the level of the codebook from which codevectors are selected is determined by a threshold.
Abstract: A variable rate vector quantization method employs a tree structured codebook. The level of the codebook from which codevectors are selected is determined by a threshold. The threshold varies according to the fullness of a buffer which stores vector quantized data to be transmitted.

58 citations

Patent
Bruno Clerckx1, Jin Kyu Han1
04 Oct 2011
TL;DR: In this article, a method for transmitting and receiving a codebook subset restriction bitmap is provided, which includes bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a user equipment (UE).
Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, 4 and 1 bits for layers 1, 2, 3, 4, 5, 6, 7 and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3 and 4, respectively.

58 citations

Journal ArticleDOI
TL;DR: The authors present a new approach to combined source-channel vector quantization, derived within information theory and probability theory, that utilizes deterministic annealing to avoid some local minima that trap conventional descent algorithms such as the generalized Lloyd algorithm.
Abstract: The authors present a new approach to combined source-channel vector quantization. The method, derived within information theory and probability theory, utilizes deterministic annealing to avoid some local minima that trap conventional descent algorithms such as the generalized Lloyd algorithm. The resulting vector quantizers satisfy the necessary conditions for local optimality for the noisy channel case. They tested the method against several versions of the noisy channel generalized Lloyd algorithm on stationary, first order Gauss-Markov sources with a binary symmetric channel. The method outperformed other methods under all test conditions, with the gains over noisy channel GLA growing with the codebook size. The quantizers designed using deterministic annealing are also shown to behave robustly under channel mismatch conditions. As a comparison with a separate source-channel system, over a large range of test channel conditions, the method outperformed a bandwidth-equivalent system incorporating a Hamming code. Also, for severe channel conditions, the method produces solutions with explicit error control coding. >

57 citations

Journal ArticleDOI
TL;DR: An iterative gradient ascent algorithm is proposed for designing a codebook for the analog and digital BF/combining matrices based on a vector quantization approach and achieves an ergodic rate improvement of up to 0.4 bits per channel use compared with the Gaussian input scenario.
Abstract: Recently, there has been significant research effort toward achieving high data rates in the millimeter wave bands by employing large antenna systems. These systems are considered to have only a fraction of the RF chains compared with the total number of antennas and employ analog phase shifters to steer the transmit and receive beams in addition to the conventional beamforming (BF)/combining invoked in the baseband domain. This scheme, which is popularly known as hybrid BF, has been extensively studied in the literature. To the best of our knowledge, all the existing schemes focus on obtaining the BF/combining matrices that maximize the system capacity computed using a Gaussian input alphabet. However, this choice of matrices may be suboptimal for practical systems, since they employ a finite input alphabet, such as quadrature amplitude modulation/phase-shift keying constellations. Hence, in this paper, we consider a hybrid BF/combining system operating with a finite input alphabet and optimize the analog as well as digital BF/combining matrices by maximizing the mutual information (MI). This is achieved by an iterative gradient ascent algorithm that exploits the relationship between the minimum mean-squared error and the MI. Furthermore, an iterative algorithm is proposed for designing a codebook for the analog and digital BF/combining matrices based on a vector quantization approach. Our simulation results demonstrate that the proposed gradient ascent algorithm achieves an ergodic rate improvement of up to 0.4 bits per channel use (bpcu) compared with the Gaussian input scenario. Furthermore, the gain in the ergodic rate achieved by employing the vector quantization-based codebook is about 0.5 bpcu compared with the Gaussian input scenario.

57 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023217
2022495
2021237
2020383
2019432
2018364