scholarly journals Practical designs for out-of-band emission suppression and adjacent channel interference rejection for orthogonal frequency division multiplexing-based cognitive radios

2015 ◽  
Vol 2015 (1) ◽  
Author(s):  
Juan Fang ◽  
I-Tai Lu
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Cognitive Radios ◽  
Frequency Division Multiplexing ◽  
Interference Rejection ◽  
Frequency Division ◽  
Adjacent Channel Interference ◽  
Band Emission ◽  
Channel Interference ◽  
Adjacent Channel

scholarly journals Spectral Emission Mask Shaping for OFDM in Cognitive Radios

2022 ◽  
pp. 166-171
Author(s):  
Ms. Swarnita Gorakshnath Kale ◽  
Prof. Kale G. B.
Keyword(s):  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Cognitive Radios ◽  
Frequency Division ◽  
Spectral Emission ◽  
Script Language ◽  
Spectral Leakage ◽  
Adjacent Channel Interference ◽  
Channel Interference ◽  
Adjacent Channel

Orthogonal frequency division multiplexing (OFDM) is characterized by spectral efficiency. It enables flexible and agile spectrum allocation. But still it lags as it suffers from spectral leakage in the form of large side lobes. It leads to inter-channel interference if not handled carefully.in proposed system spectral emission mask system is implemented to combat spectral leakage and ultimately avoiding adjacent channel interference. A spectral mask, also known as a channel mask or transmission mask is a mathematically-defined set of lines applied to the levels of radio (or optical) transmissions. The spectral mask is generally intended to reduce adjacent-channel interference by limiting excessive radiation at frequencies beyond the necessary bandwidth. The proposed system is implemented over MATLAB platform using script language.

A Digital Pre-Distortion Scheme for CMMB Repeater System Based on Dynamic Neural Networks

2013 ◽  
Vol 336-338 ◽  
pp. 1738-1743
Author(s):  
Ze Biao Lin ◽  
Chun Hui Huang
Keyword(s):  
Neural Networks ◽  
Computer Simulation ◽  
Memory Effect ◽  
Orthogonal Frequency Division Multiplexing ◽  
Bayesian Regularization ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Dynamic Neural Networks ◽  
Adjacent Channel ◽  
First Time

CMMB technology employs Orthogonal Frequency Division Multiplexing (OFDM) modulation with 4096 subcarriers for 8MHz bandwidth mode, HPA in the CMMB repeater will cause significant distortion and spectral extension. To compensate HPA nonlinearity and memory effect in a CMMB repeater system, this paper proposed a pre-distortion scheme based on RNN and Bayesian Regularization for the first time. Computer simulation is used to confirm the validation of the proposed scheme and an adjacent channel leakage ratio (ACLR) improvement of 20 dB is obtained in the paper.

scholarly journals Comparing f-OFDM and OFDM Performance for MIMO Systems Considering a 5G Scenario

2019 ◽  
Author(s):  
Felipe Augusto Pereira de Figueiredo ◽  
Nathália F. T. Aniceto ◽  
Jorge Seki ◽  
Ingrid Moerman ◽  
Gustavo Fraidenraich
Keyword(s):  
Mobile Communications ◽  
Orthogonal Frequency Division Multiplexing ◽  
Error Probability ◽  
Mimo Systems ◽  
Radio Spectrum ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Primary Users ◽  
Band Emission ◽  
Spectral Localization

The advances mobile communications has seen in recent years has rendered the radio spectrum a limited and, hence, an expensive resource. Therefore, technologies that support unlicensed access to spectrum are needed. Therefore, the adoption of novel modulation schemes becomes of utmost importance to obtain better spectral-localization and reduce the OOBE (\textit{Out of Band Emission}) inherent to OFDM (\textit{Orthogonal Frequency Division Multiplexing}) and, consequently, mitigating the interference between secondary (\textit{unlicensed}) and primary users. In this scenario, we assess the gain in the bit error probability using f-OFDM (\textit{filtered-OFDM}) in MIMO systems, both used in the 5G RANGE project.

scholarly journals Comparing f-OFDM and OFDM Performance for MIMO Systems Considering a 5G Scenario

2019 ◽  
Author(s):  
Felipe Augusto Pereira de Figueiredo ◽  
Nathália F. T. Aniceto ◽  
Jorge Seki ◽  
Ingrid Moerman ◽  
Gustavo Fraidenraich
Keyword(s):  
Mobile Communications ◽  
Orthogonal Frequency Division Multiplexing ◽  
Error Probability ◽  
Mimo Systems ◽  
Radio Spectrum ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Primary Users ◽  
Band Emission ◽  
Spectral Localization

The advances mobile communications has seen in recent years has rendered the radio spectrum a limited and, hence, an expensive resource. Therefore, technologies that support unlicensed access to spectrum are needed. Therefore, the adoption of novel modulation schemes becomes of utmost importance to obtain better spectral-localization and reduce the OOBE (\textit{Out of Band Emission}) inherent to OFDM (\textit{Orthogonal Frequency Division Multiplexing}) and, consequently, mitigating the interference between secondary (\textit{unlicensed}) and primary users. In this scenario, we assess the gain in the bit error probability using f-OFDM (\textit{filtered-OFDM}) in MIMO systems, both used in the 5G RANGE project.

Non-linear companding scheme for peak-to-average power ratio (PAPR) reduction in generalized frequency division multiplexing

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Shiv Om Tiwari ◽  
Rajeev Paulus
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Mobile Phone Technology ◽  
Time Frequency ◽  
Band Emission ◽  
Non Linear ◽  
Papr Performance

AbstractDue to the evolution of mobile phone technology which enables the use of Internet, the demand for data rates has increased tremendously. Therefore, current 4G-LTE (long-term evolution) technology needs to be replaced in near future. Hence, currently possible solutions for 5G technology are heavily investigated. Generalized frequency division multiplexing (GFDM) is one such technique which is based on multi-carrier filters and uses time-frequency structure to optimize delay and out-of-band emission (OOB). Still GFDM is very much similar to orthogonal frequency division multiplexing (OFDM) with much improved spectral and peak-to-average power ratio (PAPR) performance. This paper presents a detailed description of GFDM technique, along-with its comparison to OFDM method. This paper further investigates the non-linear companding scheme which can be used to further reduce PAPR. Simulation results are presented to obtain (Power Spectral Density) PSD and PAPR performance.

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