Codebook

About: Codebook is a research topic. Over the lifetime, 8492 publications have been published within this topic receiving 115995 citations.

Limited Feedback Precoding for Massive MIMO

Abstract: The large-scale array antenna system with numerous low-power antennas deployed at the base station, also known as massive multiple-input multiple-output (MIMO), can provide a plethora of advantages over the classical array antenna system. Precoding is important to exploit massive MIMO performance, and codebook design is crucial due to the limited feedback channel. In this paper, we propose a new avenue of codebook design based on a Kronecker-type approximation of the array correlation structure for the uniform rectangular antenna array, which is preferable for the antenna deployment of massive MIMO. Although the feedback overhead is quite limited, the codebook design can provide an effective solution to support multiple users in different scenarios. Simulation results demonstrate that our proposed codebook outperforms the previously known codebooks remarkably.

Automatic quality control for wavelet-based compression of volumetric medical images using distortion-constrained adaptive vector quantization

Abstract: The enormous data of volumetric medical images (VMI) bring a transmission and storage problem that can be solved by using a compression technique. For the lossy compression of a very long VMI sequence, automatically maintaining the diagnosis features in reconstructed images is essential. The proposed wavelet-based adaptive vector quantizer incorporates a distortion-constrained codebook replenishment (DCCR) mechanism to meet a user-defined quality demand in peak signal-to-noise ratio. Combining a codebook updating strategy and the well-known set partitioning in hierarchical trees (SPIHT) technique, the DCCR mechanism provides an excellent coding gain. Experimental results show that the proposed approach is superior to the pure SPIHT and the JPEG2000 algorithms in terms of coding performance. We also propose an iterative fast searching algorithm to find the desired signal quality along an energy-quality curve instead of a traditional rate-distortion curve. The algorithm performs the quality control quickly, smoothly, and reliably.

Data processing method, data transmission method, data reception method, apparatus, codebook, computer program product, computer program distribution medium

Abstract: The invention is related to a data processing method comprising: selecting from at least one codebook a codebook and at least one weight in the codebook fulfilling a predetermined performance criterion, wherein one of the at least one codebook is of the formula (I): and informing the selected at least one codebook and weight to a transmitter for being used in transmission.

Adaptive Precoding Codebooks for Wireless Communications

Abstract: Adaptive precoding codebooks are described. In one embodiment, the method of wireless communication includes reading at least a rank-2 baseline codebook having codewords representing precoding matrices. An adaptive codebook is generated by multiplying a first column of the codeword with a first transform matrix calculated from a channel correlation matrix, and multiplying a second column of the codeword with a second transform matrix calculated from the channel correlation matrix. The first and the second transform matrices are orthogonal.

Method and device for fast algebraic codebook search in speech and audio coding

Abstract: A method and device for searching an algebraic codebook during encoding of a sound signal, wherein the algebraic codebook comprises a set of codevectors formed of a number of pulse positions and a number of pulses distributed over the pulse positions. In the algebraic codebook searching method and device, a reference signal for use in searching the algebraic codebook is calculated. In a first stage, a position of a first pulse is determined in relation with the reference signal and among the number of pulse positions. In each of a number of stages subsequent to the first stage, (a) an algebraic codebook gain is recomputed, (b) the reference signal is updated using the recomputed algebraic codebook gain and (c) a position of another pulse is determined in relation with the updated reference signal and among the number of pulse positions. A codevector of the algebraic codebook is computed using the positions of the pulses determined in the first and subsequent stages, wherein a number of the first and subsequent stages corresponds to the number of pulses in the codevectors of the algebraic codebook.