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In this study, an efficient decoding algorithm is proposed to decode non-binary low-density parity-check (LDPC) codes. The algorithm is derived from the belief-propagation (BP) decoding with genetic algorithm of binary LDPC codes. For the proposed algorithm, two decoding constraints are introduced to determine variable nodes which are considered highly reliable. The messages from these highly reliable...
In this paper, we focus on the construction of a type of quasi-cyclic low-density-parity-check (QC LDPC) codes called cycle codes. Based on our previous work, the maximum cycle entropy (MCE) algorithm for constructing nonbinary LDPC codes can be extended to its QC form (QC-MCE), which maintains the QC structure of the parity-check matrix. With this method employed, an elegant distribution of nonzero...
With the deployment of the fourth generation communication networks, mobile video broadcast services are becoming one of the essential parts of users' daily lives. As an efficient way for mobile video transmission, digital broadcast scheme is faced with the challenge of cliff effect. A novel real-value scheme called SoftCast can eliminate the cliff effect, but not efficient in removing inter- frame...
The performance of the mobile video broadcast is weakened when applying the traditional broadcast scheme which is forced to pick a single bit rate supported by the worst receiver. It leads to the drawback that receivers with better channels cannot obtain better video qualities. This paper proposed distributed Realcast, an analog video delivery scheme based on real value transmission, to provide differentiated...
With the maturity of 4G communication technologies and the popularity of smart devices, services over mobile devices are getting more and more popular, especially the mobile video services. In this paper, we propose a mobile video broadcast framework to provide each user with the most appropriate video quality according to his channel characteristic. To meet the demands of scalability and robustness,...
Limited to the traditional digital transmission design which forces the source to pick a single bit rate supported by the worst receiver to transmit data, the mobile video broadcast service cannot provide better video qualities to the receivers with better channels. This paper proposes an analog coding and transmission scheme named Realcast to provide channel adaptive video broadcast service. It utilizes...
Wireless video multicast has become one of the key technologies to wireless applications. But the main challenge of wireless video multicast, i.e. the “cliff effect”, remains to be solved. SoftCast is a novel video coding and transmission scheme which allocates power to different coefficient chunks and transmits analog signals directly without quantization and entropy coding. It can solve the “cliff...
Wireless video transmission is one of the main applications of wireless local area networks. And high-speed video transmission can be achieved with the application of MIMO-OFDM technologies. But the conventional digital video transmission in MIMO has to degrade performances of all the antennas to be the same as the antenna with the worst channel gain. Based on H.264/AVC and ParCast, a hybrid digital-analog...
With the Radio frequency identification (RFID) is widely used in commercial, there is a growing need for quickly identifying multiple tags which is a major application of RFID. The collision of signals from different tags becomes a challenge when dealing with multiple-target situation. This paper proposed a RFID scheme using compressive sensing (CS). It treats the collision signals as useful measurements...
Distributed Compressed Video Sensing (DCVS) has developed as one of the efficient solutions that guarantee low complexity video compression. In this paper, a novel DCVS algorithm with unequal protection of the video signal's elements is proposed. The new algorithm utilizes not only the sparsity and probability distribution of the video signal but also its particular unequal significance feature. Based...
In conventional distributed video coding (DVC), we exploit a random irregular check matrix to realize LDPC coding. However, for DVC this method does not fully exploit the character that the bits corresponding to this random matrix with different significance can be protected in different degrees. Therefore, in this paper we propose an improved LDPC coding scheme with motion decision to improve the...
Distributed joint source-channel coding technique is finding its application in the ever evolving world of telecommunication, especially in the sensor network paradigm. The unique characteristics of the sensor networks are giving birth to new signal processing techniques and shifting the processing burden from the transmitter to the receiver side. The nodes of sensor networks, when deployed over particular...
A design of video capture system based on FPGA is presented in this paper. This paper describes the working principle of the system and hardware architecture and it analyzes the composition of the system modules and the design methods in detail. This paper also gives a detailed analysis of each implementation technology of the system, and the system meets the needs of the back-end of video processing...
Compressed sensing (CS) theory shows that it is possible to reconstruct exactly a sparse signal from fewer linear measurements than that would be expected from traditional sampling theory. Orthogonal matching pursuit (OMP) is a kind of greedy pursuit algorithms that could implement CS signal recovery. However, in distributed compressed sensing (DCS) scenario, an emerging field based on the correlation...
In this paper we have presented a novel idea to optimize the performance of Low Density Parity Check (LDPC) Codes by using selective encoding and decoding approach. We have also proposed a new simplified form of parity check matrix, h named as beacon matrix which is useful for the efficient implementation of the proposed scheme. The proposed scheme is more suitable for real time applications like...
Distributed compression of correlated sources has been discussed much in wireless sensor networks, while the error-resilient implementation of this efficient coding strategy is one of the crucial issues for applications. In this paper, a symmetric Distributed Joint Source-Channel Coding (DJSCC) scheme is proposed by using Raptor codes for the independent channels case. The channel noise and the correlation...
In this paper, we will discuss universal decoding problem for Slepian-Wolf (SW) systems, as we know, for the first time. Based on former literature, we give a different interpretation for minimum entropy decoder and propose a relaxed linear programming decoding algorithm. With low computational complexity, the decoding algorithm can practically settle the universal decoding problems of SW systems.
Multiple nodes sensing the common target is the most popular application of the Wireless Sensor Networks (WSNs). Pure distributed compression of multiple correlated sources has been discussed much in the related literature, while taking the noisy communication channels into account is more suitable for the actual scenario. In this paper, a practical Distributed Joint Source-Channel Coding (DJSCC)...
Orthogonal space-time block codes are a class of STBC which can achieve full diversity gain but typically loss of code rate. Quasi-orthogonal space-time code (QOSTBC) can achieve full code rate. However, they loss part of diversity gain. Generalized ABBA (GABBA) STBC is a improve QOSTBC, which can achieve full diversity gain, and also can overcome the drawback that unable to transmit with full rate...
A communication system using multilayer coded modulation is introduced to detail the basic principles of hierarchical combined equalization based on linear minimum mean square error (MMSE) algorithm. A simplified hierarchical equalizer's extrinsic information of base-layer for 4-QAM multilayer coded modulation is presented. A new hierarchical equalization method of base layer is applied to multilayer...
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