Labeling Diversity for 2x2 WLAN Coded-Cooperative Networks

Labelling diversity is an efficient technique recently proposed in the literature and aims to improve the bit error rate(BER) performance of wireless local area network (WLAN) systems with two transmit and two receive antennas without increasing the transmit power and bandwidth requirements. In this paper, we employ labelling diversity with different space-time channel codes such as convolutional, turbo and low density parity check (LDPC) for both point-to-point and coded-cooperative communication scenarios. Joint iterative decoding schemes for distributed turbo and LDPC codes are also presented. BER performance bounds at an error floor (EF) region are derived and verified with the help of numerical simulations for both cooperative and non-cooperative schemes. Numerical simulations show that the coded-cooperative schemes with labelling diversity achieve better BER performances and use of labelling diversity at the source node significantly lowers relay outage probability and hence the overall BER performance of the coded-cooperative scheme is improved manifolds

Interleaving Gains for Receive Diversity Schemes of Distributed Turbo Codes in Wireless Half–Duplex Relay Channels

This paper proposes the interleaving gain in two different distributed turbo-coding schemes: Distributed Turbo Codes (DTC) and Distributed Multiple Turbo Codes (DMTC) for half-duplex relay system as an extension of our previous work on turbo coding interleaver design for direct communication channel. For these schemes with half-duplex constraint, the source node transmits its information with the parity bit sequence(s) to both the relay and the destination nodes during the first phase. The relay received the data from the source and process it by using decode and forward protocol. For the second transmission period, the decoded systematic data at relay is interleaved and re-encoded by a Recursive Systematic Convolutional (RSC) encoder and forwarded to the destination. At destination node, the signals received from the source and relay are processed by using turbo log-MAP iterative decoding for retrieving the original information bits. We demonstrate via simulations that the interleaving gain has a large effect with DTC scheme when we use only one RSC encoder at both the source and relay with best performance when using Modified Matched S-Random (MMSR) interleaver. Furthermore, by designing a Chaotic Pseudo Random Interleaver (CPRI) as an outer interleaver at the source node instead of classical interleavers, our scheme can add more secure channel conditions

RS Codes and Optimized Distributed RS-Coded Relay Cooperative Communications: Code Constructions and Performance Analysis

This chapter introduces the Reed-Solomon (RS) codes and the distributed RS-coded cooperative system over the Rayleigh fading channel, where the encoding and decoding procedures of the RS codes are elaborated. Besides, two optimized selection approaches, i.e., the exhaustive search approach and partial search approach, are employed in the relay to obtain a resultant code at the destination with better weight distribution. Moreover, the two joint decoding algorithms, namely naive and smart algorithms, are presented that further improve the overall average bit error rate (BER) performance of the cooperative scheme. Also, the performance analysis of the distributed RS-coded cooperative scheme is provided in detailed

Joint design of QC-LDPC codes for coded cooperation system with joint iterative decoding

In this paper, we investigate joint design of quasi-cyclic low-density-parity-check (QC-LDPC) codes for coded cooperation system with joint iterative decoding in the destination. First, QC-LDPC codes based on the base matrix and exponent matrix are introduced, and then we describe two types of girth-4 cycles in QC-LDPC codes employed by the source and relay. In the equivalent parity-check matrix corresponding to the jointly designed QC-LDPC codes employed by the source and relay, all girth-4 cycles including both type I and type II are cancelled. Theoretical analysis and numerical simulations show that the jointly designed QC-LDPC coded cooperation well combines cooperation gain and channel coding gain, and outperforms the coded noncooperation under the same conditions. Furthermore, the bit error rate performance of the coded cooperation employing jointly designed QC-LDPC codes is better than those of random LDPC codes and separately designed QC-LDPC codes over AWGN channels.http://www.tandfonline.comtoc/tetn20hb2017Electrical, Electronic and Computer Engineerin

Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

Validation and integration tests of the JUNO 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO will be able to study the neutrino mass ordering and to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, the electronic system has to meet specific tight requirements, and a thorough characterization is required. The present paper describes the tests performed on the readout modules to measure their performances.Comment: 20 pages, 13 figure

Mass testing of the JUNO experiment 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%

Turbo Coded OFDM Combined with MIMO Antennas Based on Matched Interleaver for Coded-Cooperative Wireless Communication

A turbo coded cooperative orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO) antennas scheme is considered, and its performance over a fast Rayleigh fading channel is evaluated. The turbo coded OFDM incorporates MIMO (2 × 2) Alamouti space-time block code. The interleaver design, and its placement always plays a vital role in the performance of a turbo coded cooperation scheme. Therefore, a code-matched interleaver (CMI) is selected as an optimum choice of interleaver and is placed at the relay node. The performance of the CMI is evaluated in a turbo coded OFDM system over an additive white Gaussian noise (AWGN) channel. Moreover, the performance of the CMI is also evaluated in the turbo coded OFDM system with MIMO antennas over a fast Rayleigh fading channel. The modulation schemes chosen are Binary Phase shift keying (BPSK), Quadrature phase shift keying (QPSK) and 16-Quadrature amplitude modulation (16QAM). Soft-demodulators are employed along with joint iterative soft-input soft-output (SISO) turbo decoder at the destination node. Monte Carlo simulated results reveal that the turbo coded cooperative OFDM system with MIMO antennas scheme incorporates coding gain, diversity gain and cooperation gain successfully over the direct transmission scheme under identical conditions

<italic>N</italic>-Ary Alamouti Space-Time Block Coding With and Without Golden Codewords

Information is conveyed by either time, antenna, and/or frequency in the conventional modulation. In this paper, we propose a novel technique to convey information in Alamouti space-time block coding systems. In the proposed technique, the information can be conveyed by one channel&#x2019;s phase component with order $N$ . The proposed technique is referred to as $2\times {N_{r}}\,\,N$ -ary Alamouti-STBC ( $N$ -STBC), where $N_{r}$ is the number of receive antennas. The $N$ -STBC with Golden codewords (GCs) is further proposed to improve error performance at high signal-to-noise ratios (SNRs). Moreover, the proposed $N$ -STBC with and without GCs still preserves the orthogonal transmission matrix of the Alamouti-STBC which retains the simple linear maximum-likelihood (L-ML) detection for quasi-static frequency-flat Rayleigh fading channels. The transmitted symbols can be directly estimated by use of the L-ML detection in the $N$ -STBC with and without GCs. However, only the GCs are estimated by use of the L-ML detection in $N$ -STBC with GCs. The signal detection subset based ML detection is further employed to detect the transmitted $M$ -ary quadrature amplitue modulation (MQAM) symbols in $N$ -STBC with GCs. The lower error probability bounds of the $N$ -STBC with and without GCs are derived and validated by simulation results. As an example, the proposed $2\times 4\,\,16$ QAM 16-STBC with GCs almost maintain the error performance of the conventional Alamouti-STBC with GCs at SNRs

QC LDPC Codes for MIMO and Cooperative Networks using Two Way Normalized Min-Sum Decoding

This paper is based on the magnitude overestimation correction of the variable message by using two normalized factors in each iteration for LDPC min-sum decoding algorithm. The variable message is modified with a normalized factor when there is a sign change and with another normalized factor when there is no sign change during any two consecutive iterations. This paper incorporates QC LDPC codes using this new decoding algorithm for flat fading multiple input multiple output (MIMO) channel and single relay cooperative communication networks for improving the bit error performance. MIMO flat fading channel is used with zero forcing (ZF) spatial decoding for noise suppression. The performance is greatly enhanced by using the new min-sum algorithm for medium and short length Cooperative communication network and MIMO LDPC codes