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.
When implementing data encryption and decryption in a symmetric cryptosystem, secure distribution of the secret key to legitimate nodes can be a challenge. In this paper, we consider establishing secret keys using the common wireless channel, with particular emphasis on the spatial and temporal correlations of the channel coefficients. Specifically, we investigate the influence of channel correlation...
In this paper we introduce the implementation of a block-LDPC codec on FPGA with simulation. The result shows that this codec is suitable for block LDPC with less resource consumption.
Low density parity check code (LDPC) has constructed a flexible, low decoding complexity and performance close to Shannon limit benefits. This paper introduces the LDPC codes and bit-interleaved coded modulation with iterative decoding (BICM-ID) scheme, given its log-likelihood ratio belief propagation (LLR-BP) decoding algorithm. Achieved with LDPC codes as component codes in BICM-ID scheme is applied...
Low Density Parity Check (LDPC) codes have been adopted in a number of wired and wireless communication standards due to their improved error correcting ability and relatively simple decoder structure. However, for very high throughput systems operating in the multi-Gb/s range conventional decoding methods based on message passing are limited, due largely to the sheer volume of messages being exchanged...
This paper mostly concerned with the various packet size effect on performance of erasure correctable codes for cognitive radio. Among these types of codes we tried to simulate Raptor code to discover its suitability for assumed erasure channel in cognitive radio. The main target after supporting the functionality of coding-based cognitive radio would be finding the appropriate packet length that...
In order to reduce the system computation complexity and delay, we propose a scheme to decrease the iterative time of the carrier synchronization for low-density parity-check (LDPC) codes. The system will stop iteration if the log-likelihood ratio (LLR) message at the output of decoder satisfies the limitary conditions. Simulation results show that the proposed scheme is efficient and there is little...
This paper is focused on the study of layered space-time-frequency (LSTF) architectures with channel coding for orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) multiplexing systems for high speed wireless communications over a frequency-selective fading channel. In order to achieve the available spatial, temporal and frequency diversities, and also make the...
In this paper, we undertake a comparison of LDPC (768,384) and convolutional (171,133) codes for 60-GHz OFDM-based wireless communication systems. The comparison is based on two parameters: Frame Error Rate (FER) for 60-GHz channels and decoding hardware complexity for a required throughput of more than 1 Gbps. Additionally, we provide performance parameters of a fully parallel LDPC decoder chip,...
During the last few years, several authors have studied the performance of many different types of channel codes for cooperative communication systems. Some of these codes include Low Density Parity Check (LDPC), Turbo and convolutional codes. Published results show that these codes effectively improve both the data rate and system performance in cooperative schemes such as the decode and forward...
This paper focus on the lossy compression of a binary symmetric source. We propose a new algorithm for binary quantization over low density generator matrix (LDGM) codes. The proposed algorithm is a modified version of the belief propagation (BP) algorithm used in the channel coding framework and has linear complexity in the code block length. We also provide a common framework under which the proposed...
In wireless scenarios an effective protocol to increase the reliability for time-varying channels is the hybrid automatic repeat request (H-ARQ). The H-ARQ scheme with cross-packet channel coding (CPC) is a recently published extension of H-ARQ with several advantages. No full-diversity low-density parity-check (LDPC) code design for the whole range of coding rates yielding full-diversity has been...
In this paper we present a novel Hybrid Automatic Repeat reQuest (HARQ) scheme for cooperative communication systems, called Coded Partial Retransmission (CPR). The method is based on the retransmission of only a fraction of the original codeword by the cooperating nodes, applying an appropriate power allocation. Numerical results using LDPC codes and Type-I HARQ with Chase Combining show that CPR...
Adaptive network coded cooperation (ANCC) scheme has been shown to have better performance than the conventional repetition-based schemes and the space-time coded cooperation (STCC) frameworks for data transmissions from a large collection of terminals to a common destination in large wireless networks. However, the random selection strategy for ANCC protocol may generate many short cycles in the...
This paper presents a link adaptation strategy for non-binary LDPC code over a time-variant frequency-selective channel. The algorithm is based first on the adoption of waterfilling technique to wisely adapt the transmitted power. It is shown that as long as best subchannels are identified with the waterfilling algorithm, an equal power distribution can be applied with performance comparable to the...
This paper addresses the issue of encoding of LDPC codes for certain transmission standards that employ LDPC as coding scheme. It is shown that for these LDPC codes, the encoding can be done simply by reusing decoding resources with negligible overhead. Compared to conventional encoding designs, our approach requires much less resources specified for encoder.
In this paper a modified Offset Min-Sum decoding algorithm for Low-Density Parity Check Codes is presented. In this modified algorithm, the offset factor in the original Offset Min-Sum algorithm is adjusted iteratively with the assistance of the check-node computation outputs of the Normalized Min-Sum algorithm. As a result, the offset factor in our modified algorithm can be calculated adaptively...
This article designs an auto measurement and control system of the aircraft data recorder based on optical fiber transmission, this system can remote real-time monitor 5Km outside of the aircraft data recorder and read the data afterward. Data link transmission of the system uses 1B/12B encoding and decoding method in order to achieve DC-balance, which can guarantee that the remote command and data...
In this paper, we introduce a kind of high performance of concatenated code that is called parallel concatenated code. Comparing to conventional serial concatenated code, it has more matching room and higher adaptability. Moreover, burst of errors which are aroused by noise are beautiful restrained. For certifying the superiority and practicability, we research a parallel concatenated code by combining...
We consider in this paper the problem of blind frame synchronization of systems using Reed-Solomon (RS) codes and other related families. We present first of all three techniques of blind frame synchronization based on the non-binary parity check matrix of RS codes. While the first two techniques involve the calculation of hard and soft values of the syndrome elements respectively, the third one perform...
In this paper, we investigate the performance and the design of Joint Source-Channel Decoding (JSCD) schemes involving structured Low-Density Parity-Check (LDPC) codes such as protograph based codes. We first present the asymptotic analysis of such iterative receivers based on multi-dimensional EXIT charts. Since a protograph can be interpreted as different encoding schemes, the information mapping...
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.