The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Construction of high rate Space Time Block Codes (STBCs) with low decoding complexity has been studied widely using techniques such as sphere decoding and non Maximum-Likelihood (ML) decoders such as the QR decomposition decoder with M paths (QRDM decoder). Recently Ren et al., presented a new class of STBCs known as the block orthogonal STBCs (BOSTBCs), which could be exploited by the QRDM decoders...
In this paper, we propose polarization multiplexing as an ideal candidate for next-generation GNSS systems like GPS and Galileo. After describing in detail a new model of MIMO LMS channel, we show simulation results for the proposed scheme concatenated with a state-of-the-art Turbo code. A slow and a fast scenario are considered and both show that PM offers a better performance than other schemes...
Quasi-cyclic (QC) low-density parity-check (LDPC) codes are of great interest to code designers because of their implementation advantages and algebraic properties that facilitate their analysis. In this paper, we present some new results on QC-LDPC codes that are constructed using a two-step lifting procedure based on a protograph, and, by implementing this method instead of the usual one-step procedure,...
The adaptation of intensive calculation algorithms made the new emerging H.264 an efficient video codec. On the other hand, embedded processors are equipped with multicore processors, thus offering additional processing power. The H.264 codec cannot benefit from this processing power in its current state. One solution is to execute the codec on different cores concurrently. H.264 codec is a complex...
In this paper, we extend the min-sum (MS) and its two improved algorithms (i.e., the normalized MS algorithm and the offset MS algorithm) to decode fountain codes over the binary input additive white Gaussian noise (BIAWGN) channel. We use Gaussian approximation method to analyze the asymptotic performance of fountain codes under various decoding algorithms and optimize the parameters of the two improved...
This paper studies feedback based instantly decodable network coding with the aim of minimizing decoding delay per transmission over wireless broadcast erasure channels with memory. We model such channels with a Gilbert-Elliott two-state Markov model with good and bad states. We first present a weighted sum generalized instantly decodable network coding (G-IDNC) scheme, where the aim is to service...
Although belief propagation (BP) algorithm can be used to solve the problem of LT decoding on noisy channels, the system performance turns out to be not very good. In this paper, we introduce one method to improve the system performance of LT soft decoding. The method is using different percent of systematic connections of encoded packets. Simulation results reveal the advantage of the proposed modified...
Reversible data hiding is a newly developed research field in digital rights management (DRM) applications. It is a branch in watermarking researches, with the characteristics of reversibility at the decoder. Secret information can first be embedded into original image, with algorithms designed by researchers, at the encoder. Next, image containing secret data is delivered to the decoder. After reception...
In this paper we continue our study of the influence of message saturation and quantization on the error-rate performance of iterative, message-passing decoders for low-density parity-check (LDPC) codes. We extend our previous analytical results for the min-sum algorithm (MSA) and its variants to the sum-product algorithm (SPA), demonstrating the significant impact of message saturation on the appearance...
Reversible data hiding has its attractions and possible drawbacks in researches, and it has the potential to extend to digital rights management (DRM) applications. For reversible data hiding, secret information can be hidden into original multimedia content, and the content with hidden data can be transmitted to the receiver. After reception, receiver employs corresponding algorithm to decode the...
In this paper, we consider a layered decoding algorithm for a performance improvement of LDPC. The proposed algorithm is based on a serial scheduling algorithm for the layered decoding of LDPC in which we consider check node degree, variable node degree, and the edge connection between the each node. Simulation results show that the proposed method improves about 0.2dB SNR gain compared with random...
“Soft is better than hard” — this sentence explains the meaning of one of the most important innovations in coding theory during the 90's: the usage of soft output in Soft Input Soft Output decoding and the appearance of Turbo Codes. The same principle may be applied to the verification mechanisms of cryptographic check values: instead of standard or hard verification, soft verification can be used...
It has been shown that Min-Sum (MS) algorithms have low complexity in the implementation of analog VLSI decoders compared to the Sum-Product (SP) algorithm. Moreover, Turbo-structured LDPC (TS-LDPC) codes are known to have lower error floor than random LDPC codes. In this paper, Min-Sum and Min-Sum with correction factor algorithms are reviewed and adapted with TS-LDPC codes for future analog VLSI...
This paper presents an extrinsic data compression method for double-binary turbo codes. Frame and extrinsic data memory occupy more area in turbo decoder implementations with the frame size increasing. Besides, non-binary turbo codes have much more extrinsic memory usage than single-binary turbo codes. This proposed compression method utilizes an operation in radix-4 single-binary turbo decoder and...
The fixed-complexity sphere decoder (FSD) has been proposed to attain the near-optimal performance achieving the same diversity order as the maximum-likelihood decoder (MLD) recently. However, it suffers great redundant computations resulting in high power consumption. In this paper, we conduct an improved algorithm for the original FSD by using early termination (ET). This algorithm (abbreviated...
The BP decoding terminates frequently during the early stage for LT codes with the robust Soliton distribution. Generally, more than 90% of undecoded input symbols result from decoding termination within the range 0 ≤ n ≤ k/2, where n and k are the decoded and total number of input symbols, respectively. This study focuses on reducing the symbol loss probability by preventing early decoding termination...
The arithmetic coding is known as a highly efficient entropy coding. However, its encoding and decoding are time-consuming due to the symbol-by-symbol arithmetic operations. Several approaches have been proposed to reduce the computation time by replacing the multiplication with the addition, subtraction or shift operation. However, these approximations cause a loss of the coding efficiency. In this...
We consider wireless multicasting over lossy links and explore the benefit of cooperative strategies in which multicast receivers exchange messages. A key feature of the problem considered here is that the source downlink channel has a higher loss rate than the channels between pairs of receivers; this feature implies that completion time may be reduced by offloading transmissions to receiver-receiver...
A new technique for constructing the Quasi Cyclic Low density Parity Check (QC-LDPC) codes based on splitting rows into sub rows method is proposed. The proposed QC-LDPC code, at BER of 10−6 achieves 0.1dB coding gain over the PEG-LDPC codes. Moreover, in the high Eb / N0 region, the proposed code with girths 16 and 20 respectively, achieve 0.056 dB and 0.27 dB at a BER of 10−5 over the randomly constructed...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.