Simplified Trellis Research Articles

Complexity-Efficient Dependent Quantization for Versatile Video Coding

The dependent quantization (DQ) technique in Versatile Video Coding (VVC) provides high compression efficiency, but it suffers from much computation, which is not preferred in practical applications. In this context, we propose a complexity-efficient dependent quantization structure employing a machine learning-based DQ start position prediction and a simplified trellis structure. Firstly, the proposed DQ start position is decided by a binary classifier which finds an appropriate location to start the DQ process. To further reduce the processing time of the binary classification, we also set up a precondition with a learned preset threshold which can reduce the number of coefficients subjected to the classifier. Based on our statistical analysis showing that under certain conditions some branches of the trellis structure are not necessary to check, we also design a branch pruning method and a removal scheme of all-zero coefficient group checking to simplify the DQ trellis structure. Our proposed complexity-efficient DQ has much fewer calculations of rate-distortion costs. Our experimental results show that it can reduce the computational complexity of the DQ process with nearly no performance loss of Bjontegaard delta bit rate (BDBR) irrespective of the all intra or the random access configurations.

Optimization of bush structure of white Muscat grapes grown in shelter crop

In this article, the authors proposed the optimization of the bush structure of white Muscat grapes grown in a sheltered crop. Modern domestic viticulture is based on the use of industrial-type formations capable of producing the highest and highest quality yields. Industrial technology forms the basis for promising systems for vineyard management and bush formation. These technologies are best suited for the mechanization of vineyard maintenance work and allow for increased productivity and quality of work in the vineyards. The adaptive wine growing strategy is to increase production profitability by significantly increasing yields while at the same time improving product quality. A set of interrelated measures is needed to achieve this objective. These measures include improving the assortment and placement of varieties in the zones with the most favorable soil and climatic conditions. The adaptive viticulture strategy is to increase production profitability by significantly increasing yields while at the same time improving product quality. The most favorable opportunities to realize its productive potential are in simplified single-wire trellis plantations. Such plantings with long-stranded forms permit a dramatic increase in the shot load per unit area. The increased shoot capacity of the long-stranded forms and the corresponding optical characteristics of the leaf apparatus contribute to a yield increase of 1.5-2.0 times compared with conventional trellis forms.

Distortion propagation modeling and its applications on frame level quantization control for predictive video coding

Inter-frame temporal prediction in video coding causes distortion propagation among adjacent frames. As a result, frame level bit allocation and quantization control are intrinsically to be optimized with dependent rate distortion optimization (RDO). Taking inter-frame distortion propagation into consideration, quantization parameter cascading (QPC) is an efficient technique for frame level quantization control in terms of dependent RDO. This paper proposes a temporal distortion propagation model by quantitatively evaluating the temporal distortion dependency. Block-level temporal trajectory is tracked via inter-prediction on down-sampled original frames to construct the temporal analysis chain, and then tree-style dependent analysis is implemented along the trajectory. The amounts of equivalent distortion propagated from the temporally adjacent frames are quantitatively measured. Then, a new distortion model is developed to facilitate measuring the RD (rate distortion) cost in terms of dependent RDO. Finally, a simplified trellis comprised of candidate quantization parameters (Qp) of the frames within one GOP, and the optimal Qp is searched via simplified dynamic programming to achieve global optimization. The simulation results verify that the frame level QPC algorithm achieves 3.46% BD-RATE saving on average, which is contributed by efficient bit allocation along temporal trajectory.

Simplified Trellis Min–Max Decoder Architecture for Nonbinary Low-Density Parity-Check Codes

Nonbinary low-density parity-check (NB-LDPC) codes have become an efficient alternative to their binary counterparts in different scenarios, such as moderate codeword lengths, high-order modulations, and burst error correction. Unfortunately, the complexity of NB-LDPC decoders is still too high for practical applications, especially for the check node (CN) processing, which limits the maximum achievable throughput. Although a great effort has been made in the recent literature to overcome this disadvantage, the proposed decoders are still not ready for high-speed implementations for high-order fields. In this paper, a simplified trellis min–max algorithm is proposed, where the CN messages are computed in a parallel way using only the most reliable information. The proposed CN algorithm is implemented using a horizontal layered schedule. The overall decoder architecture has been implemented in a 90-nm CMOS process for a ( $N=837$ and $K=726$ ) NB-LDPC code over GF(32), achieving a throughput of 660 Mb/s at nine iterations based on postlayout results. This decoder increases hardware efficiency compared with the existing recent solutions for the same code.

A 40 nm 535 Mbps Multiple Code-Rate Turbo Decoder Chip Using Reciprocal Dual Trellis

This paper presents a multiple code-rate turbo decoder using the reciprocal dual trellis to improve the hardware efficiency. For a convolutional code with code rate k/(k+1), its corresponding reciprocal dual code with rate 1/(k+1) has smaller codeword space than the original code while k > 1, leading to a simplified trellis of the high code-rate code. The proposed decoder architecture can decode code rate k/(k+1) constituent convolutional codes for k=1, 2, 4, 8, and 16. Moreover, two parallel soft-in/soft-out (SISO) decoders are exploited in our turbo decoder by using the quadratic permutation polynomial (QPP) interleaver to improve the decoding speed. After fabricated in 1P9M CMOS 40 nm process, the proposed decoder with 1.27 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> core area can achieve 535 Mbps throughput at 8/9 code rate, and the energy efficiency is 0.068 nJ/bit/iteration at 0.9 V.

Effective Two-Dimensional Partial Response Maximum Likelihood Detection Scheme for Holographic Data Storage Systems

An effective two-dimensional (2D) partial response maximum likelihood (PRML) detection scheme for holographic data storage (HDS) systems is proposed. The proposed scheme adopts the simplified trellis diagram, uses a priori information, and detects the data in two directions from the previously proposed detection schemes. The simplified trellis diagram which has 4 states and 8 branches yields a dramatic complexity reduction while the simplified 2D PRML detector shows serious performance degradation in the high density HDS channels. To prevent performance degradation, the proposed detector uses a priori information in order to give higher reliability to the branch metric. Furthermore, the proposed scheme detects the data in the vertical and horizontal directions to fully utilize the characteristics of the channel detection with a 2D partial response target. By effective combination of these three techniques, the proposed scheme with a simple structure has more than 2 dB gains compared to the conventional detection schemes.

Effective Two-Dimensional Partial Response Maximum Likelihood Detection Scheme for Holographic Data Storage Systems

An effective two-dimensional (2D) partial response maximum likelihood (PRML) detection scheme for holographic data storage (HDS) systems is proposed. The proposed scheme adopts the simplified trellis diagram, uses a priori information, and detects the data in two directions from the previously proposed detection schemes. The simplified trellis diagram which has 4 states and 8 branches yields a dramatic complexity reduction while the simplified 2D PRML detector shows serious performance degradation in the high density HDS channels. To prevent performance degradation, the proposed detector uses a priori information in order to give higher reliability to the branch metric. Furthermore, the proposed scheme detects the data in the vertical and horizontal directions to fully utilize the characteristics of the channel detection with a 2D partial response target. By effective combination of these three techniques, the proposed scheme with a simple structure has more than 2 dB gains compared to the conventional detection schemes.

Simplified multi-track detection schemes using a priori information for bit patterned media recording

Simplified multi-track detection schemes using a priori information for bit patterned magnetic recording (BPMR) are proposed in this paper. The proposed detection schemes adopt the simplified trellis diagram, use a priori information, and detect the main-track data in the along- and cross-track directions. The simplified trellis diagram, which has 4 states and 8 branches, can be obtained by setting the corner entries of the generalized partial response (GPR) target to zero and replacing the four parallel branches with a single branch. However, these simplified techniques seriously suffer from performance degradation in high density BPMR channels. To overcome the performance degradation, a priori information is used to give higher reliability to the branch metric. In addition, to fully use the characteristics of channel detection with a two-dimensional (2D) GPR target, the proposed schemes estimate a priori information and detect the main-track data in the along- and cross-track directions by using a 2D equalizer with a 2D GPR target. The bit error rate performances of the proposed schemes are compared with the previous detection schemes when areal density is 3 Tb/in2. Simulation results show that the proposed schemes with simpler structures have more than 2 dB gains compared with the other detection schemes.

Stereo Matching Algorithm Using a Simplified Trellis Diagram Iteratively and Bi-Directionally

This paper presents an approach that uses the Viterbi algorithm in a stereo correspondence problem. We propose a matching process which is visualized as a trellis diagram to find the maximum a posterior result. The matching process is divided into two parts: matching the left scene to the right scene and matching the right scene to the left scene. The last result of stereo problem is selected based on the minimum error for uniqueness by a comparison between the results of the two parts of matching process. This makes the stereo matching possible without explicitly detecting occlusions. Moreover, this stereo matching algorithm can improve the accuracy of the disparity image, and it has an acceptable running time for practical applications since it uses a trellis diagram iteratively and bi-directionally. The complexity of our proposed method is shown approximately as O(N2 × P), in which N is the number of disparity, and P is the length of the epipolar line in both the left and right images. Our proposed method has been proved to be robust when applied to well-known samples of stereo images such as random dot, Pentagon, Tsukuba image, etc. It provides a 95.7 percent of accuracy in radius 1 (differing by ±1) for the Tsukuba images.

Simplified trellis diagram for a simple partial erasure model

In this letter, a simplified trellis diagram for the simple partial erasure model introduced by Lee, Yamauchi, and Cioffi [1994] is presented. This new trellis has fewer states, fewer branches, and a smaller radix than the aforementioned. Based on this trellis, conventional Viterbi decoding achieves maximum likelihood sequence detection.

Simplified trellis decoder

A new simplified trellis decoder (STD) Viterbi-type algorithm is proposed for fast trellis decoding of rate K/K+1 binary convolutional codes. Viterbi algorithm (VA) computation is dominated by add-compare-select (ACS) operations when k/spl ges/2. The STD can substantially reduce the number of ACS operations and allow for a trade-off between the computational load and the performance of the decoder, The STD is analyzed and simulated for a four-dimensional (4-D) rate 4/5 64-state convolutional encoder specified by the ITU-T V.34 modem recommendation.

Decoding performance of linear block codes using a trellis in digital mobile radio

Trellis decoding of linear block codes in a Rayleigh fading channel is discussed. Two methods for calculating metric values for each bit in a received block are considered: the values are calculated from the received signal envelope sample and from the demodulator output. Bit error rate (BER) performances of hard decision and trellis decoding are compared using Hamming (7, 4) and Golay (24, 12) codes in computer simulations and laboratory experiments. A simplified trellis decoding algorithm, in which the hard decision output of a bit with an envelope sample greater than the threshold value is accepted as correct, is presented. Laboratory experimental results for trellis decoding in combination with Gaussian minimum-shift-keying (GMSK) modulation and frequency detection are shown. The effect of n-bit A/D-conversion in signal envelope sampling is investigated experimentally. The results show that the trellis decoding algorithm improves BER performance. >