scholarly journals Uni-Cycle Genetic Algorithm as an Adaptation Engine for Wireless Channel Equalizers

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 171
Author(s):  
Mohammed J. Khafaji ◽  
Maciej Krasicki

A recently developed adaptive channel equalizer driven by a so-called Uni-Cycle Genetic Algorithm (UCGA) is examined in the paper. The authors consider different initialization strategies of the iterative process and compare UCGA against the reference Recursive Least Squares (RLS) algorithm in terms of Bit Error Rate (BER) vs. Signal to Noise Ratio (SNR) performance and convergence rate of an adaptive channel equalizer. The results display a reasonable performance gain of UCGA over RLS for most of wireless channel models studied in the paper. Additionally, UCGA is capable of boosting the equalizer convergence. Thus, it can be considered a promising candidate for the future adaptive wireless channel equalizer.

Author(s):  
Akhil Gupta ◽  
Shiwani Dogra ◽  
Ishfaq Bashir Sofi

Background & Objective: In this paper, Multiple Input Multiple Output (MIMO) has been examined in wireless medium by utilizing Spatial Multiplexing procedure for the computation of the Bit Error Rate (BER). MIMO enhance the throughput in wireless medium. Spatial multiplexing builds the limit and link reliability of the MIMO frameworks. Methods: The BER execution of DPSK, Phase Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM) in MIMO frameworks in Rayleigh multipath channel is analyzed. Zero forcing algorithms is utilized as a detection technique. A comparison of these modulations is additionally done in Rayleigh fading channel. Conclusion: The execution of transmission modes are assessed by figuring the likelihood of Bit Error Rate (BER) vs. the Signal Noise Ratio (SNR) under the every now and utilized four wireless channel models (Rayleigh, Dent, Jake’s and Okumura).


2021 ◽  
Vol 107 ◽  
pp. 182-193
Author(s):  
Aliyu Ahmed ◽  
Adeyemi Abel Ajibesin

The essence of my paper is to intricately look at data transfer with various modulation techniques over various communication channels. And run simulations to uncover the Bit Error Rate (BER) of various relevant scenarios. I will evaluate the performance of modulation techniques from Binary Phase Shift Keying (BPSK or 2PSK) to 16PSK and other modulation techniques with the consideration of time. Their performance will be evaluated and analyzed by calculating their probability of bit error rate (BER) versus the Energy per bit to spectral noise density (Eb/No) over various wireless channel models such as the Additive White Gaussian Noise (AWGN), Rayleigh channel and Ricean channel. My simulation results will graphically display the effective performance of each communication scenario; it will give us a better understanding of why performances of data communications techniques.


Author(s):  
Gebremedhn Wubet Wagaye

<p>The noise introduced in the channel obviously affects the bit error rate of the communication system and this has direct impact in the security. Here the main problem is that the receiver terminal decoding techniques can lead to wrong interpretation even if the Bit Error Rate (BER) is acceptable. So the main idea here is to introduce high values of Signal to Noise Ratio (SNR) that can improve the bit error rate which exists due to the noise introduced in the wireless channel.</p>


2020 ◽  
Vol 25 (2) ◽  
pp. 86-97
Author(s):  
Sandy Suryo Prayogo ◽  
Tubagus Maulana Kusuma

DVB merupakan standar transmisi televisi digital yang paling banyak digunakan saat ini. Unsur terpenting dari suatu proses transmisi adalah kualitas gambar dari video yang diterima setelah melalui proses transimisi tersebut. Banyak faktor yang dapat mempengaruhi kualitas dari suatu gambar, salah satunya adalah struktur frame dari video. Pada tulisan ini dilakukan pengujian sensitifitas video MPEG-4 berdasarkan struktur frame pada transmisi DVB-T. Pengujian dilakukan menggunakan simulasi matlab dan simulink. Digunakan juga ffmpeg untuk menyediakan format dan pengaturan video akan disimulasikan. Variabel yang diubah dari video adalah bitrate dan juga group-of-pictures (GOP), sedangkan variabel yang diubah dari transmisi DVB-T adalah signal-to-noise-ratio (SNR) pada kanal AWGN di antara pengirim (Tx) dan penerima (Rx). Hasil yang diperoleh dari percobaan berupa kualitas rata-rata gambar pada video yang diukur menggunakan metode pengukuran structural-similarity-index (SSIM). Dilakukan juga pengukuran terhadap jumlah bit-error-rate BER pada bitstream DVB-T. Percobaan yang dilakukan dapat menunjukkan seberapa besar sensitifitas bitrate dan GOP dari video pada transmisi DVB-T dengan kesimpulan semakin besar bitrate maka akan semakin buruk nilai kualitas gambarnya, dan semakin kecil nilai GOP maka akan semakin baik nilai kualitasnya. Penilitian diharapkan dapat dikembangkan menggunakan deep learning untuk memperoleh frame struktur yang tepat di kondisi-kondisi tertentu dalam proses transmisi televisi digital.


Author(s):  
Faxin Qi ◽  
Xiangrong Tong ◽  
Lei Yu ◽  
Yingjie Wang

AbstractWith the development of the Internet and the progress of human-centered computing (HCC), the mode of man-machine collaborative work has become more and more popular. Valuable information in the Internet, such as user behavior and social labels, is often provided by users. A recommendation based on trust is an important human-computer interaction recommendation application in a social network. However, previous studies generally assume that the trust value between users is static, unable to respond to the dynamic changes of user trust and preferences in a timely manner. In fact, after receiving the recommendation, there is a difference between actual evaluation and expected evaluation which is correlated with trust value. Based on the dynamics of trust and the changing process of trust between users, this paper proposes a trust boost method through reinforcement learning. Recursive least squares (RLS) algorithm is used to learn the dynamic impact of evaluation difference on user’s trust. In addition, a reinforcement learning method Deep Q-Learning (DQN) is studied to simulate the process of learning user’s preferences and boosting trust value. Experiments indicate that our method applied to recommendation systems could respond to the changes quickly on user’s preferences. Compared with other methods, our method has better accuracy on recommendation.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yuan Ding ◽  
Yunhua Zhang ◽  
Vincent Fusco

A 10 GHz Fourier Rotman lens enabled dynamic directional modulation (DM) transmitter is experimentally evaluated. Bit error rate (BER) performance is obtained via real-time data transmission. It is shown that Fourier Rotman DM functionality enhances system security performance in terms of narrower decodable low BER region and higher BER values associated with BER sidelobes especially under high signal to noise ratio (SNR) scenarios. This enhancement is achieved by controlled corruption of constellation diagrams in IQ space by orthogonal injection of interference. Furthermore, the paper gives the first report of a functional dual-beam DM transmitter, which has the capability of simultaneously projecting two independent data streams into two different spatial directions while simultaneously scrambling the information signals along all other directions.


2018 ◽  
Vol 11 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sandeep Kaushal ◽  
Bambam Kumar ◽  
Dharmendra Singh

AbstractIn through the wall imaging systems, wall parameters like its thickness and dielectric constant play an important role in the true and correct image formation of an object behind the wall made of various materials like brick cement, wood, plastic, etc. Incorrect estimation of these parameters leads to dislocation of the object and smearing or blurriness of the image too. A new autofocusing technique for a stepped frequency continuous wave -based radar at the frequency of 1–3 Ghz has been developed that corrects the wall's parameters like its thickness and dielectric constant and provides a better focused image of the target. For this purpose, a peak signal to noise ratio -based autofocusing technique has been developed by using curve fitting and the genetic algorithm. It is observed that the proposed technique has capability to focus the image up to good extent.


Signals ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 1-10
Author(s):  
Md. Noor-A-Rahim ◽  
M. Omar Khyam ◽  
Apel Mahmud ◽  
Xinde Li ◽  
Dirk Pesch ◽  
...  

Long-range (LoRa) communication has attracted much attention recently due to its utility for many Internet of Things applications. However, one of the key problems of LoRa technology is that it is vulnerable to noise/interference due to the use of only up-chirp signals during modulation. In this paper, to solve this problem, unlike the conventional LoRa modulation scheme, we propose a modulation scheme for LoRa communication based on joint up- and down-chirps. A fast Fourier transform (FFT)-based demodulation scheme is devised to detect modulated symbols. To further improve the demodulation performance, a hybrid demodulation scheme, comprised of FFT- and correlation-based demodulation, is also proposed. The performance of the proposed scheme is evaluated through extensive simulation results. Compared to the conventional LoRa modulation scheme, we show that the proposed scheme exhibits over 3 dB performance gain at a bit error rate of 10−4.


2007 ◽  
Vol 4 (8) ◽  
pp. 13
Author(s):  
Alexander Galvis Quintero ◽  
Cristina Gómez Santamaría ◽  
Roberto Hincapié

2012 ◽  
Vol 241-244 ◽  
pp. 2491-2495 ◽  
Author(s):  
Antonio Boscolo ◽  
Francesca Vatta ◽  
Francesco Armani ◽  
Emanuele Viviani ◽  
Daniele Salvalaggio

This paper presents a physical channel emulator solution for applications such as Bit Error Rate Testing of Error Correcting Codes. The solution relies on an analog White Gaussian Noise Generator coupled additively with an analog data signal to emulate the communication channel. This is interfaced to a computer through a USB connection, allowing the use of programs in different environments, such as Matlab and Labview. This solution can allow different types of channels to be emulated and with different noise sources. A software-based method to measure Signal to Noise Ratio and to characterize the channel is also presented. The system has been validated using a Matlab interface implementing multiple error correcting codes and showed good agreement with the theoretical model.


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