Joint Subcarrier and Power Allocation for Uplink Spectrum Sharing in Cognitive OFDM Networks: A Waterfilling Based Approach

2013 ◽  
Vol 756-759 ◽  
pp. 1979-1983 ◽  
Author(s):  
Yue Huai Ma ◽  
Bin Zhang ◽  
Wei Zhang ◽  
Meng Xiang Xu
Keyword(s):  
Power Allocation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Spectrum Sharing ◽  
Cognitive Radio Network ◽  
Frequency Division Multiplexing ◽  
Radio Network ◽  
Frequency Division ◽  
Allocation Algorithm ◽  
Primary Network ◽  
Simulation Results

In this paper, the subcarrier and power allocation problem for the orthogonal frequency division multiplexing (OFDM) cognitive radio network which coexists with the primary network is studied. A cognitive waterfilling (CWF) power allocation algorithm which based upon the classical waterfilling mechanism is proposed for the single SU scenario. As for multi-SU case, we present an efficient joint subcarrier and power allocation algorithm called MS-CWF algorithm. Simulation results show the effectiveness of the proposed CWF and MS-CWF algorithms.

The Waterfilling Based Subcarrier and Power Allocation for OFDM Cognitive Radio Networks

2012 ◽  
Vol 601 ◽  
pp. 406-412
Author(s):  
Yue Huai Ma ◽  
Dong Mei Zhang ◽  
You Yun Xu
Keyword(s):  
Cognitive Radio ◽  
Power Allocation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Cognitive Radio Network ◽  
Low Complexity ◽  
Radio Networks ◽  
Secondary Users ◽  
Allocation Algorithm ◽  
Primary Network ◽  
Primary Receiver

In this paper, the subcarrier and power allocation problem for the orthogonal frequency division multiplexing (OFDM) cognitive radio network which coexists with the primary network is studied. Specifically, in consideration of both transmit power constraints of secondary users and interference power constraint at each primary receiver. A cognitive waterfilling (CWF) power allocation algorithm which based upon the classical waterfilling mechanism is proposed for the single SU and multi-PU scenario. As for the multi-SU and multi-PU case, we present an efficient joint subcarrier and power allocation algorithm called MS-CWF algorithm with low complexity. Simulation results show the effectiveness of the proposed CWF and MS-CWF algorithms.

scholarly journals A CCM-Based OFDM System with Low PAPR for Sparse Source

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Qinbiao Yang ◽  
Zulin Wang ◽  
Qin Huang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Coded Modulation ◽  
High Peak ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm System ◽  
Simulation Results ◽  
Clipping And Filtering

Orthogonal frequency division multiplexing (OFDM) usually suffers high peak-to-average power ratio (PAPR). As shown in this paper, PAPR becomes even severe for sparse source due to many identical nonzero frequency OFDM symbols. Thus, this paper introduces compressive coded modulation (CCM) in order to restrain PAPR by reducing identical nonzero frequency symbols for sparse source. As a result, the proposed CCM-based OFDM system, together with iterative clipping and filtering, can efficiently restrain the high PAPR for sparse source. Simulation results show that it outperforms about 4 dB over the traditional OFDM system when source sparsity is 0.1.

scholarly journals Design of QAM-OFDM Radar-Communication Integrated Signal Based on Golay Complementary sequences

2021 ◽  
Vol 2085 (1) ◽  
pp. 012010
Author(s):  
Ming Kun Ye ◽  
Qin Zhu ◽  
Peng Cheng Dai ◽  
Jun Tang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Detection Performance ◽  
Utilization Rate ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Detection Ability ◽  
Complementary Sequences ◽  
Gold Sequences ◽  
Simulation Results ◽  
Correlation Performance

Abstract The integration of radar and communication is conducive to improving the utilization rate of hardware resources and spectrum. To address the issue that the communication information in orthogonal frequency division multiplexing (OFDM) integrated signal for radar and communication affects detection performance, an OFDM integrated signal for radar and communication based on precoding was proposed. The communication information of the integrated signal was pre-coded by using the Gray Complementary Sequences (GCS) with better correlation performance to improve the performance of the ambiguity function of the integrated signal and its detection ability. Simulation results show that GCS have better correlation performance compared to M and Gold sequences, and the OFDM integrated signal pre-coded by GCS has lower Peak Sidelobes Ratio (PSLR) and comparable radar performance to LFM.

Beyond 3G Techniques of Orthogonal Frequency Division Multiplexing and Performance Analysis via Simulation

2013 ◽  
pp. 135-147
Author(s):  
Chunyan Wang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Great Weight ◽  
Spectrum Utilization ◽  
Beyond 3G ◽  
Single Carrier ◽  
Effective Performance ◽  
Simulation Results ◽  
And Performance

As one of the techniques beyond 3G, because of the effective performance of high spectrum utilization and anti-fading for frequency selecting and adopted multi-carrier modulation technique that meets the requirement of the explosive traffic capacity, Orthogonal Frequency Division Multiplexing (OFDM) has carried great weight in wireless communications. This paper expounds OFDM technical characteristics and performs computer simulation on the OFDM system based on Inverse Fast Fourier Transform (IFFT) by means MATLAB. During the course of simulation, comparison between OFDM and traditional single-carrier technology is performed. The simulation results have great significance for research and applications in the field.

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