Software-defined radio based baseband discrete model for orthogonal frequency division multiplexing CDMA systems

Author(s):  
Xiaojun Wu ◽  
Bofeng Jiang ◽  
Qinye Yin
2018 ◽  
Vol 1 (2) ◽  
pp. 282-292
Author(s):  
Daniel Ricardo Pérez-Riaño ◽  
Elkin Andrés Ducuara-Hernández ◽  
Luis Fernando Pedraza-Martínez

In this paper the performance of a Generalized Frequency Division Multiplexing waveform is evaluated when compared to an Orthogonal Frequency Division Multiplexing signal. For the development of the previous waveforms, the GNU radio software and the Software Defined Radio (SDR) equipment USRP N210 are used. Through a spectrum analyzer the power of both waveforms are measured and the Out-of-Band Radiation is analyzed. Then, the results obtained are compared and the advantages and disadvantages of the implementation of GFDM as a waveform within the fifth generation systems are exposed.


2021 ◽  
Vol 20 ◽  
pp. 68-80
Author(s):  
Dia Mohamad Ali ◽  
Zhraa Zuheir Yahya

Filtered-orthogonal frequency division multiplexing (F-OFDM) is a quasi-orthogonal waveform candidate for the applications of the fifth generation (5G) communication system. In this study, an F-OFDM waveform with unequal sub-band sizes is proposed to improve the spectrum efficiency (SE) of the 5G system. The proposed waveform is modeled with the Blackman window-sinc filter and is developed based on the software-defined radio (SDR) technology for practical implementation. The result shows that the F-OFDM performance of the simulation and hardware implementation is approximately the same. The SE using the proposed F-OFDM waveform is 6% and 5.8% higher than the SE using the conventional OFDM waveform under the simulation in the LabVIEW NXG simulator and under the practical use in the universal software radio peripheral (USRP) platform, respectively.


2019 ◽  
Vol 4 (1) ◽  
pp. 64-69
Author(s):  
BB Harianto

Salah satu permasalahan dalam perkembangan teknologi telekomunikasi yaitu bagaimana mencapai data rate yang besar namun dengan bandwidth yang tidak lebih besar dari bandwidth koheren kanal untuk menghindari terjadinya Inter-Symbol Interference (ISI). Salah satu solusi yang ditawarkan yaitu transmisi multi-carrier. Cara kerja transmisi multi-carrier yaitu membagi total bandwidth signal yang tersedia menjadi beberapa subcarrier-subcarrier dengan bandwidth yang sempit. Sehingga bandwith masingmasing subcarrier yang dihasilkan tersebut menjadi lebih kecil jika dibandingkan dengan bandwidth koheren kanal. Salah satu transmisi multicarrier yang terbaru yaitu Orthogonal Frequency Division Multiplexing (OFDM) dimana subcarrier-subcarrier dapat saling tegak lurus satu sama lain sehingga bendwidth yang dibutuhkan menjadi lebih efisien jika dibandingkan dengan multicarrier konvensional seperti FDM. Sistem OFDM dapat diimplementasikan pada USRP yang merupakan salah satu jenis SDR (Software Defined Radio). SDR merupakan sistem pemancar dan penerima yang menggunakan pemrosesan sinyal digital untuk coding, decoding, modulasi dan demodulasi data. USRP tersebut digunakan sebagai model pemancar dan penerima pada pengukuran kualitas unjuk kerja sistem OFDM dengan barbagai kondisi. Pengukuran ini akan membandingkan hasil performansi parameter – parameter pada frekwensi 910 MHz dan 2.4 GHz. Spesifikasi sistem OFDM yang digunakan pada penelitian ini menggunakan software Labview dan dilakukan pada lingkungan indoor pada jarak 3m dan bandwidth 1 MHz. Hasil dari implementasi dan pengukuran menunjukkan bahwa parameter yang ditunjukkan oleh frekwensi 910 MHz lebih baik dari pada nilai parameter yang ditunjukkan oleh frekwensi 2.4


2021 ◽  
Author(s):  
Sumit Gautam ◽  
Sumit Kumar ◽  
Symeon Chatzinotas ◽  
Bjorn Ottersten

The possibility to harvest energy from ambient radio-frequency (RF) sources has intrigued humankind since past several decades. In this context, there has been a tremendously growing research interest in the field of wireless power transfer (WPT) using the RF regime of the electromagnetic (EM) spectrum. In this paper, we investigate the aspect of real-time energy harvesting (EH) via different types of waveform designs such as Orthogonal Frequency Division Multiplexing (OFDM), Square, Triangular, Sinusoidal, and Sawtooth. We make use of a Software Defined Radio (SDR) and a Powercast P21XXCSREVB EH module to carry out the experiments on practical device performance. Specifically, we are interested in obtaining some insights based on the comparison between the aforementioned waveform designs from the perspectives of separation distance between the USRP and P21XXCSR-EVB EH module, and power emission via USRP. Correspondingly, the demonstration of the EH is provided in terms of the above-mentioned investigation metrics, while seeking the best waveform to support WPT.


2021 ◽  
Author(s):  
Sumit Gautam ◽  
Sumit Kumar ◽  
Symeon Chatzinotas ◽  
Bjorn Ottersten

The possibility to harvest energy from ambient radio-frequency (RF) sources has intrigued humankind since past several decades. In this context, there has been a tremendously growing research interest in the field of wireless power transfer (WPT) using the RF regime of the electromagnetic (EM) spectrum. In this paper, we investigate the aspect of real-time energy harvesting (EH) via different types of waveform designs such as Orthogonal Frequency Division Multiplexing (OFDM), Square, Triangular, Sinusoidal, and Sawtooth. We make use of a Software Defined Radio (SDR) and a Powercast P21XXCSREVB EH module to carry out the experiments on practical device performance. Specifically, we are interested in obtaining some insights based on the comparison between the aforementioned waveform designs from the perspectives of separation distance between the USRP and P21XXCSR-EVB EH module, and power emission via USRP. Correspondingly, the demonstration of the EH is provided in terms of the above-mentioned investigation metrics, while seeking the best waveform to support WPT.


Ingenius ◽  
2019 ◽  
pp. 74-85
Author(s):  
Juan Paúl Inga Ortega ◽  
Anthony Yanza Verdugo ◽  
Christian Pucha Cabrera

Este trabajo propone la aplicación de un estimador de canal basado en sensado compresivo (CS, del inglés Compressive Sensing) sobre un sistema que usa multiplexación por división de frecuencias ortogonales (OFDM, del inglés Orthogonal Frequency Division Multiplexing) usando dispositivos de radio definido por \emph{software} (SDR, del inglés Software Defined Radio). La aplicación de la teoría de CS se da a través del uso de algoritmos de reconstrucción dispersa como Orthogonal Matching Pursuit (OMP) y Compressive Sampling Matching Pursuit (CoSaMP) con el fin de aprovechar la naturaleza dispersa de las subportadoras piloto usadas en OFDM optimizando el ancho de banda del sistema. Además, para mejorar el rendimiento de estos algoritmos, se utiliza el concepto de la matriz de comprobación de paridad dispersa que se implementa en el despliegue de códigos de comprobación de paridad de baja densidad (LDPC, del inglés Low Density Parity Check) para obtener una matriz de sensado que mejore la propiedad de restricción isométrica (RIP, del inglés Isometric Restriction Property) perteneciente al paradigma de CS. El documento muestra el modelo implementado en los equipos SDR analizando la tasa de error de bit y la cantidad de símbolos piloto usados.


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