scholarly journals Constructing LDPC Codes with Any Desired Girth

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2012
Author(s):  
Chaohui Gao ◽  
Sen Liu ◽  
Dong Jiang ◽  
Lijun Chen
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Power Consumption ◽  
Experimental Evidence ◽  
Ldpc Codes ◽  
Wireless Sensor ◽  
Low Density ◽  
Parity Check ◽  
Optimal Input ◽  
Low Density Parity Check

In wireless sensor networks, the reliability of communication can be greatly improved by applying low-density parity-check (LDPC) codes. Algorithms based on progressive-edge-growth (PEG) pattern and quasi-cyclic (QC) pattern are the mainstream approaches to constructing LDPC codes with good performance. However, these algorithms are not guaranteed to remove all short cycles to achieve the desired girth, and their excellent inputs are difficult to obtain. Herein, we propose an algorithm, which must be able to construct LDPC codes with the girth desired. In addition, the optimal input to the proposed algorithm is easy to find. Theoretical and experimental evidence of this study shows that the LDPC codes we construct have better decoding performance and less power consumption than the PEG-based and QC-based codes.

FPGA Implementation of a Novel Multi-Rate QC-LDPC Encoder for DTMB Standard

2013 ◽  
Vol 397-400 ◽  
pp. 2024-2027
Author(s):  
Fei Wang ◽  
Peng Zhang ◽  
Chang Yin Liu
Keyword(s):  
Power Consumption ◽  
Ldpc Codes ◽  
Fpga Implementation ◽  
Type I ◽  
Low Density ◽  
Parity Check ◽  
Encoding Scheme ◽  
Low Density Parity Check ◽  
Memory Resource ◽  
Simulation Results

A serial-input serial-output encoder based on pipelined type I rotate-left-accumulator (RLA) circuit is presented for multi-rate Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) codes of Digital Terrestrial Multimedia Broadcasting (DTMB) standard. This encoding scheme can reduce the power consumption and save memory resource. FPGA implementation and simulation results show that the design meets the requirement of DTMB standard and simplifies the structure of the memory.

scholarly journals Self-Organization of Activity in Wireless Sensor Networks

2005 ◽  
Vol 1 (2) ◽  
pp. 245-252 ◽  
Author(s):  
P. Davis ◽  
A. Hasegawa ◽  
N. Kadowaki ◽  
S. Obana
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Power Consumption ◽  
Wireless Sensors ◽  
Ad Hoc ◽  
Wireless Sensor ◽  
Self Organization ◽  
Sensor Systems ◽  
Low Resolution ◽  
Sensing Data

We propose a method for managing the spontaneous organization of sensor activity in ad hoc wireless sensor systems. The wireless sensors exchange messages to coordinate responses to requests for sensing data, and to control the fraction of sensors which are active. This method can be used to manage a variety of sensor activities. In particular, it can be used for reducing the power consumption by battery operated devices when only low resolution sensing is required, thus increasing their operation lifetimes.

scholarly journals A New Reliability Ratio Weighted Bit Flipping Algorithm for Decoding LDPC Codes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chakir Aqil ◽  
Ismail Akharraz ◽  
Abdelaziz Ahaitouf
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Ldpc Codes ◽  
Low Density ◽  
Parity Check ◽  
Coding Gain ◽  
Decoding Complexity ◽  
Low Density Parity Check ◽  
Awgn Channel ◽  
Infinite Loop

In this study, we propose a “New Reliability Ratio Weighted Bit Flipping” (NRRWBF) algorithm for Low-Density Parity-Check (LDPC) codes. This algorithm improves the “Reliability Ratio Weighted Bit Flipping” (RRWBF) algorithm by modifying the reliability ratio. It surpasses the RRWBF in performance, reaching a 0.6 dB coding gain at a Binary Error Rate (BER) of 10−4 over the Additive White Gaussian Noise (AWGN) channel, and presents a significant reduction in the decoding complexity. Furthermore, we improved NRRWBF using the sum of the syndromes as a criterion to avoid the infinite loop. This will enable the decoder to attain a more efficient and effective decoding performance.

scholarly journals Energy-Efficient Method for Wireless Sensor Networks Low-Power Radio Operation in Internet of Things

2020 ◽  
Author(s):  
Mehdi Amiri Nasab ◽  
Shahaboddin Shamshirband ◽  
Anthony Theodore Chronopoulos ◽  
Amir Mosavi ◽  
Narjes Nabipur
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Internet Of Things ◽  
Power Consumption ◽  
Low Power ◽  
Time Factors ◽  
Wireless Sensor ◽  
Common Source ◽  
Factors Affecting ◽  
Duty Cycles

The radio operation in wireless sensor networks (WSN) in the Internet of Things (IoT) applications are the most common source for power consumption. However, recognizing and controlling the factors affecting radio operation can be valuable for managing the node power consumption. ContikiMAC is a low-power Radio Duty-Cycle protocol in Contiki OS used in WakeUp mode, which is a clear channel assessment (CCA) to check radio status periodically. The time spent to check the radio is of utmost importance for monitoring power consumption. It can lead to false WakeUp or idle listening in Radio Duty-Cycles and ContikiMAC. This paper presents a detailed analysis of radio WakeUp time factors of ContikiMAC. Then, we propose lightweight CCA (LW-CCA) as an extension to ContikiMAC to reduce the percentage of Radio Duty-Cycles in false WakeUps and idle listenings by using dynamic received signal strength indicators (RSSI) status check time. The simulation results in the Cooja simulator show that LW-CCA reduces about 8% energy consumption in nodes while maintaining up to 99% of the packet delivery rate (PDR).

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