Concatenated Channel Coding Research Articles

Performance Evaluation of Serial and Parallel Concatenated Channel Coding Scheme With Non-Orthogonal Multiple Access for 6G Networks

In recent years, with the advent of 6G and intelligent devices, sensors, and new applications such as virtual reality and autonomous driving, user data traffic has exploded, especially video traffic and small IoT packets. These bandwidth-hungry applications require an increased network capacity and user access. The 6G network may use nonorthogonal multiple access (NOMA) instead of orthogonal multiple access (OMA) to maintain higher data rates, throughput, and lower latency. On the other hand, choosing the channel coding method for future 6G mobile communication is critical for maintaining the high demand for 6G. This paper proposes two-channel coding structures to achieve higher data rates with a lower error rate floor; these structures are polar convolutional serial code (PCSC) and polar convolutional parallel code (PCPC); these structures can achieve a larger channel capacity and reduced bit error rates when used with NOMA. The obtained simulation results showed that bit error rate (BER) performance improves the overall coding gain by 1.2 dB compared to polar code in fifth-generation (5G). PCSC surpasses PCPC with a 1.5dB coding gain. This performance ranged from 4 to 6.25dB with higher system settings. The obtained throughput results showed an improvement of 56-60%, in which the enhancement percentage depended on the modulation method used in a direct proportion manner.

IMPLEMENTATION OF FPGA-BASED DVB-T2 TRANSMITTER FOR A SECOND GENERATION DIGITAL TERRESTRIAL TELEVISION BROADCASTING SYSTEM

Nowadays, with strong development of Science and Technology, integrated circuits continue to dominate not only in the field of digital information. Over the last several years, Technological television industry has taken huge strides and powerful transformation to meet with government’s policy about digitization of television all over the country in period 2015 – 2020. Stemming from the practical needs of “localization of products” and mastering of technological design of DVB-T2 transmitter (Digital Video Broadcasting – Terrestrial for Second generation), the authors have made an effort to research in algorithm, designed and tested in Field Programmable Gate Array (FPGA) technology. DVB-T2 is mainly aimed to replace the current standard DVB-T. The main motivation of DVB-T2 is to provide broadcasters with more advanced and efficient alternative to DVB-T standards. In DVB-T2 transmitter system, digital audio, video, and other data are compressed into a single signal to be transmitted on a single RF channel, using orthogonal frequency-division multiplexing (OFDM) with concatenated channel coding and interleaving. The higher offered bit rate makes it a suited system for carrying HDTV signals on the terrestrial TV channel. The next generation broadcasting systems should be designed to make full use of spectral resources while providing reliable transmissions in order to enable services like multichannel HDTV (High Definition Television) and innovative data casting services. The efficient usage of the radio spectrum can be achieved by the introduction of Single Frequency Networks (SFN). Digital transmitter DVB-T2 implemented on FPGA using a software Xilinx System Generator for DSP tool and Xilinx ISE Design Suite 14.7. System Generator for DSP is in conjunction on environment MATLAB-Simulink that is capable of simulating the proposed hardware structures that is synthesized and implemented by the programmable elements in Field-programmable Gate Arrays. In this project, adaptative MPEG-TS bitrate converter is designed to allows to increasing or reducing the MPEG TS rate by adding or filtering NULL packets. The entire digital transmitter DVB-T2 is integrated in one chip Xilinx FPGA Kintex-7 XC7K325T-1FFG676. Experimental design on development Kit NetFPGA-1G-CML of Digilent Corporation is performed at design department of technology center of Vietnamese Communications Television Development JSC. Authors are continuing to improve products, put into practical applications to replace the digital terrestrial television broadcasting stations that are being used in Vietnam. The article named “Implementation of FPGA-based DVB-T2 transmitter for a second generation digital terrestrial television broadcasting system” presents the research results, design methods, test results to compare, evaluate the accuracy of algorithm implementation. The results open up new directions for technological television in Vietnam.

Improving the Performance of Chaos-Based Modulations Via Serial Concatenation

This paper proposes a serially concatenated system with an outer convolutional channel encoder and an inner chaos-based coded modulator. With the help of the principles of symbolic dynamics, the chaotic modulation can be described in terms of a trellis. Owing to this, we show that the resulting system can be designed and analyzed following developments made for serially concatenated channel codes (SCCCs) or bit-interleaved coded-modulation systems. We show how the iterative decoding algorithm used in this concatenated framework can be analyzed through the well-known extrinsic information transfer chart device and how the bit error rate can be bounded using the transfer function of the convolutional channel encoder. Comparison with a related SCCC system in both additive white Gaussian noise and frequency-nonselective fading channels shows that this kind of chaos-based systems keeps the potential advantages of coded-modulation-based systems. We are thus confident that the principles shown here can lead to the design of competitive chaotic discrete communication systems.

Turbo decoding of concatenated channel coding and trellis shaping for peak power controlled single-carrier systems

Trellis shaping (TS) has found its application in the peak power control of band-limited single-carrier signals. Our recent work has demonstrated that a well-designed TS can control the symbol transitions such that the output signal has almost constant envelope, which significantly alleviates the linearity requirement of power amplifiers. Compared to transmission without constellation shaping, however, the TS involves signal constellation expansion exclusively for peak power control. Therefore, unlike trellis coded modulation (TCM) that increases the minimum Euclidean distances (MED), the TS decreases the MED, thus incurring the increase in signal-to-noise power ratio (SNR) required for achieving a certain error rate. In this letter, in order to overcome this drawback, we propose a serial concatenation of coding and shaping together with an effective decoding algorithm that utilizes the memory effect (i.e., error correcting capability) of the shaped symbols. The achievable performance of the proposed system is analyzed in terms of the average mutual information. The simulation results demonstrate that the iterative decoding of the proposed concatenated system with outer convolutional codes and inner trellis shaping offers a significant performance gain.

BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

In this paper, we investigate the bit error rate (BER) performance of a concatenated low density parity check (LDPC) encoded orthogonal frequency-division multiplexing (OFDM) system on color image transmission. In FEC concatenated channel coding, the OFDM wireless communication system incorporates 1/2-rated convolution encoder under various digital modulations (QPSK, 8PSK, QAM, 8QAM, 16QAM and 32QAM) over an additative white gaussian noise (AWGN) and other fading (Raleigh and Rician) channels. Computer simulation results on BER demonstrate that the LDPC encoded OFDM system outperforms with QAM modulation technique as compared to other digital modulation scheme and the system is highly effective to combat inherent interferences under Rayleigh and Rician fading channels. The transmitted color image is found to have retrieved effectively under noisy and fading situations with implementation of sum-product algorithm, an effective iterative based LDPC decoding scheme. It has also been anticipated that the performance of the communication system degrades with the increasing of noise power. Keywords: Orthogonal frequency division multiplexing (OFDM); Low density parity check (LDPC); Bit error rate (BER). © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2724 J. Sci. Res. 2 (1), 46-53 (2010)

Error Probability Bounds of Concatenated Channel Codes and Differential Space-Time Block Codes

In this letter, we analyze the performance of a class of multiple-antenna systems which concatenate channel codes, e.g., trellis coded modulation (TCM), and differential orthogonal space-time block codes (DOSTBC). Assuming no channel state information (CSI), tight performance bounds for bit and frame error rates are provided under block Rayleigh fading channel. Simulation results are also provided which confirm the accuracy of analytical findings.

Performance of concatenated channel codes and orthogonal space-time block codes

In this paper we analyze the performance of an important class of MIMO systems that of orthogonal space-time block codes concatenated with channel coding. This system configuration has an attractive combination of simplicity and performance. We study this system under spatially independent fading as well as correlated fading that may arise from the proximity of transmit or receive antennas or unfavorable scattering conditions. We consider the effects of time correlation and present a general analysis for the case where both spatial and temporal correlations exist in the system. We present simulation results for a variety of channel codes, including convolutional codes, turbo codes, trellis coded modulation (TCM), and multiple trellis coded modulation (MTCM), under quasi-static and block-fading Rayleigh as well as Rician fading. Simulations verify the validity of our analysis

Performance of Serially Concatenated Channel Coding with Space Time Block Coding in OFDM Transmission System

Telah diketahui bahawa kepelbagaian ruang–masa dengan menggunakan kodan ruang–masa (STC) adalah satu teknik yang berkesan dalam memperbaiki prestasi perhubungan wayarles. STC direka untak saluran pemudaran rata dan ia terdiri daripada kodan trellis ruang–masa (STTC) dan kodan blok ruang–masa (STBC). STTC boleh memberikan gandaan kepelbagaian dan gandaan pengekodan dengan melibatkan kos dari segi kekompleksan nyahkodan. Sebaliknya, STBC hanya membekalkan gandaan kepelbagaian tetapi mengurangkan kekompleksan nyahkodan. Dalam kertas kerja ini, kami membentangkan skema kod Bose–Chauduri Hocquengheim (BCH) siri terangkai dengan STBC daripada rekaan ortogon (STBC–OD) untuk mendapatkan gandaan kepelbagaian dan juga gandaan pengekodan dalam sistem ini. Kami juga melibatkan sistem penghantaran OFDM dalam skema yang dibentangkan untuk mengekalkan prestasi pada saluran pudaran memilih berbilang–laluan. Prestasi sistem ini diselidiki apabila pemodulatan penguncian anjakan fasa pada kadar–penuh, kadar–separuh, dan kadar–3/4 dengan menggunakan bilangan antena penghantar yang bersesuaian. Keputusan penyelakuan menunjukkan bahawa sistem yang dibentangkan ini dapat memperbaiki gandaan SNR berbanding dengan skema tidak terkod yang berkaitan. Maklumat keadaan saluran dianggap boleh sedia ada di penerima. Kata kunci: BCH, STBC-OD, OFDM It is well known that space–time diversity using space–time coding (STC) is an effective technique to improve wireless communication performance. STC was designed for flat fading channel and consists of space–time trellis code (STTC) and space–time block code (STBC). STTC has provided diversity gain and coding gain in the cost of decoding complexity. On the other hand, STBC only provides diversity gain but simple in decoding complexity. Thus, in this paper, we proposed serially concatenated Bose–Chauduri Hocquengheim (BCEI) code with STBC from orthogonal design (STBC–OD) scheme to provide diversity gain and also coding gain in the system. We incorporated OFDM transmission system onto our proposed scheme to maintain the performance over multipath selective fading channels. Performance of the system was investigated when M–ary phase shift keying (M–PSK) modulation was used for full–rate, half–rate, and three quater–rate of transmission employing appropriate number of transmit antennas. Simulation results showed that the proposed system has improved the SNR gain over the related uncoded schemes. Channel state information was assumed available at the receiver. Key words: BCH, STBC-OD, OFDM

High-Rate Recursive Convolutional Codes for Concatenated Channel Codes

This letter presents the results of the search for optimum punctured recursive convolutional codes (RCCs) of rate k/k+1, for k=2,...,8, suitable for concatenated channel codes whose constituent encoders are recursive, systematic convolutional codes. The mother codes that are punctured are rate-1/2 RCCs proposed for use in parallel and/or serial concatenation schemes. Extensive tables of systematic and nonsystematic puncturing patterns, optimized relative to various objective functions suitable for concatenated channel codes, are presented for several mother codes.

Space-time codes and concatenated channel codes for wireless communications

Following a brief historical perspective on channel coding, an introduction to space-time block codes is given. The various space-time codes considered are then concatenated with a range of channel codecs, such as convolutional and block-based turbo codes as well as conventional and turbo trellis codes. The associated estimated complexity issues and memory requirements are also considered. These discussions are followed by a performance study of various space-time and channel-coded transceivers. Our aim is first to identify a space-time code/channel code combination constituting a good engineering tradeoff in terms of its effective throughput, bit-error-rate performance, and estimated complexity. Specifically, the issue of bit-to-symbol mapping is addressed in the context of convolutional codes (CCs) and convolutional coding as well as Bose-Chaudhuri-Hocquenghem coding-based turbo codes in conjunction with an attractive unity-rate space-time code and multilevel modulation is detailed. It is concluded that over the nondispersive or narrow-band fading channels, the best performance versus complexity tradeoff is constituted by Alamouti's twin-antenna block space-time code concatenated with turbo convolutional codes. Further comparisons with space-time trellis codes result in similar conclusions.

Space-time codes and concatenated channel codes for wireless communications [Prolog

Space-time codes and concatenated channel codes for wireless communications [Prolog

Space-time codes and concatenated channel codes for wireless communications

Following a brief historical perspective on channel coding, an introduction to space-time block codes is given. The various space-time codes considered are then concatenated with a range of channel codecs, such as convolutional and block-based turbo codes as well as conventional and turbo trellis codes. The associated estimated complexity issues and memory requirements are also considered. These discussions are followed by a performance study of various space-time and channel-coded transceivers. Our aim is first to identify a space-time code/channel code combination constituting a good engineering tradeoff in terms of its effective throughput, bit-error-rate performance, and estimated complexity. Specifically, the issue of bit-to-symbol mapping is addressed in the context of convolutional codes (CCs) and convolutional coding as well as Bose-Chaudhuri-Hocquenghem coding-based turbo codes in conjunction with an attractive unity-rate space-time code and multilevel modulation is detailed. It is concluded that over the nondispersive or narrow-band fading channels, the best performance versus complexity tradeoff is constituted by Alamouti's twin-antenna block space-time code concatenated with turbo convolutional codes. Further comparisons with space-time trellis codes result in similar conclusions.

Experimental evaluation of combined postdetection diversity and concatenated channel coding

The combined effects of postdetection diversity reception and concatenated channel coding are experimentally evaluated for /spl pi//4-shift QDPSK signal transmission over a Rayleigh fading channel. Two-branch postdetection diversity reception using maximal ratio combining (MRC) and selection combining (SC) are considered. The concatenated channel coding uses the Reed-Solomon (15,k) code of GP(2/sup 4/) as the outer code and the BCH (7,4) code as the inner code (k=9,11,13). Measured bit error rate (BER) performance results are presented under cochannel interference (CCI) and multipath channel delay spread, as well as additive white Gaussian noise (AWGN).< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>