scholarly journals Performances of BICM-ID system using CRSC code in optical transmissions

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hocine Fekih ◽  
Boubakar Seddik Bouazza ◽  
Keltoum Nouri

AbstractRecently, using iterative decoding algorithms to achieve an interesting bit error rate for spectrally efficient modulation become a necessity for optical transmission, in this paper, we propose a coded modulation scheme based on bit interleaving circular recursive systematic convolutional (CRSC) code and 16-QAM modulation. The proposal system considered as a serial concatenation of a channel encoder, a bit interleaver and M-ary modulator can be flexible easy to implement using a short code length. For a spectral efficiency $\eta =3\text{bit}/s/Hz$, the coding gain at a bit error rate of 10−6 is about 8 dB.

2012 ◽  
Vol 195-196 ◽  
pp. 901-903
Author(s):  
Jun Wu ◽  
Xiao Bo Wu

Trellis coded (TCM) modulation can obtain the coding gain without increase the transmission power and the bandwidth but it can not obtain diversity gain, and space-time block code (STBC) can provide diversity gain in a simple encoding and decoding way, though its coding gain is not very satisfied. This article will achieve a STBC-class networking trellis coded modulation scheme based on FPGA to further study the performance of the concatenated code.


2001 ◽  
Vol 37 (3) ◽  
pp. 187 ◽  
Author(s):  
K. Yonenaga ◽  
A. Sano ◽  
M. Yoneyama ◽  
S. Kuwahara ◽  
Y. Miyamoto ◽  
...  

In this paper reduction of errors in turbo decoding is done using neural network. Turbo codes was one of the first thriving attempt for obtaining error correcting performance in the vicinity of the theoretical Shannon bound of –1.6 db. Parallel concatenated encoding and iterative decoding are the two techniques available for constructing turbo codes. Decrease in Eb/No necessary to get a desired bit-error rate (BER) is achieved for every iteration in turbo decoding. But the improvement in Eb/No decreases for each iteration. From the turbo encoder, the output is taken and this is added with noise, when transmitting through the channel. The noisy data is fed as an input to the neural network. The neural network is trained for getting the desired target. The desired target is the encoded data. The turbo decoder decodes the output of neural network. The neural network help to reduce the number of errors. Bit error rate of turbo decoder trained using neural network is less than the bit error rate of turbo decoder without training.


Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 620
Author(s):  
Ari Endang Jayati ◽  
Wirawan ◽  
Titiek Suryani ◽  
Endroyono

Generalized frequency division multiplexing (GFDM) with offset quadrature amplitude modulation (OQAM) is an alternative non-orthogonal modulation scheme for future generation wireless broadband systems. The nonlinearity of high power amplifiers (HPAs) has a very significant effect on the performance of GFDM systems. In this paper, we investigate the effects of nonlinear distortion on the multiple-input multiple-output (MIMO)-GFDM system when the signal is passed the HPA, which is modeled with amplitude and phase distortion. The effects of nonlinear distortion due to the HPA include amplitude distortion, phase distortion, and the spread of signal constellations. These effects also produce harmonic signals and intermodulation outside the frequency band which results in spectral spread. This will then reduce the performance of the MIMO-GFDM system. The contributions of this paper concern three key areas. Firstly, we investigate the effects of nonlinear distortion on the MIMO-GFDM system. We also derive the new closed-form expression bit error rate (BER) in MIMO-GFDM systems that use a memoryless HPA, which is modeled using the Saleh model when passed through the additive white Gaussian noise (AWGN) channel. This model was chosen because it is simple and has AM/AM and AM/PM curves. Secondly, we propose the application of techniques for the linearization of each HPA predistorter on the transmitter side of the MIMO-GFDM system separately. This predistorter is able to compensate for nonlinear distortion caused by the HPA without memory operating in the saturation region. The main contribution of this paper is to investigate the predistorter, which can linearize nonlinear distortion in MIMO-GFDM transmitters. The performance of the proposed scheme is evaluated in terms of spectrum analysis, PAPR analysis, a constellation diagram, and bit error rate (BER) analysis. The simulation results show that the proposed predistorter design succeeds in compensating for nonlinear distortions caused by the HPA for large input back-off (IBO) values.


2021 ◽  
Vol 107 ◽  
pp. 194-200
Author(s):  
Theman Ibrahim Jirnadu ◽  
Adeyemi Abel Ajibesin ◽  
Ahmed T. Ishaq

Although, most researchers focus on some of the key components of good digital wireless communications which are the Bit Error Rate (BER) versus Signal to Noise Ratio (SNR) of modulation schemes. Energy consumption optimization is necessary for enhancing the performance of a wireless communication system as it offers numerous advantages to the system and the users. Therefore, this research focuses on analyzing the efficiency in the performance of the various QAM Modulation Schemes (4QAM, 16QAM, 32QAM & 64QAM) as they travel over noise/fading channels with the quest to obtain an energy-efficient scheme which will enhance system performance in terms of system runtime and quality of service. The efficiency of any given process, operation, or device is rated per the energy it consumes in carrying out an activity per unit output. Hence, the objective of this research work is to study and analyze comparatively the efficiency of these modulation schemes and to conclude with the most efficient scheme over the various channels. The evaluation of the Bit Error Rate (BER) versus energy per bit to noise spectral density (EbNo) for each communication scenario was carried out in MATLAB.


Author(s):  
Manoj Kumar A ◽  
R V Nadagouda ◽  
R Jegan

Bit Error Rate (BER) is a principle measure of data transmission link performance. BER tester (BERT) consists of a Pattern Generator and an Analyzer that can be set to the same pattern. The payload data transmitted from the spacecraft consists of one, two or three channels per carrier based on the modulation scheme. The traditional equipments can do BER analysis for only one channel at a time. In order to support multichannel BER analysis, a Personal Computer (PC) based system is designed and implemented in Altera Stratix II (EP2S130F1508C5N) FPGA. Ethernet is configured using WIZnet 5300 (Ethernet Controller) and it is used for communication between FPGA and PC with an application. Application is used to transmit the Pattern Generator’s configurations from PC to FPGA and to receive Analyzer’s status. Packet processing is done for this communication using User Datagram protocol (UDP). On the whole, traditional equipments are replaced by the designed and implemented bit error rate tester.


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