On the effects of memoryless nonlinearities on M-QAM and DQPSK OFDM signals

Chorti, Arsenia; Brookes, Mike

doi:10.1109/tmtt.2006.879129

Cited by 17 publications

(11 citation statements)

References 27 publications

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“…The effect has been extensively evaluated in [12] in the case of 3rd order nonlinearities. Additionally, in the case of an OFDM receiver, at early stages in the down-conversion link, it is probable that at the input of the nonlinear circuit may be present adjacent channels of the same service.…”

Section: Receiver Nonlinearitiesmentioning

confidence: 99%

Performance analysis of OFDM and DAB receivers in the presence of spurious tones

Chorti

Brookes

2010

Telecommun Syst

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A number of mechanisms can result in the generation of spurious tones in Orthogonal Frequency Division Multiplexing (OFDM) receivers. In this work we determine the Signal-to-Noise-Ratio (SNR) degradation at the output of the Fast-Fourier-Transform (FFT) block and evaluate the performance of a Digital Audio Broadcasting (DAB) receiver in the presence of such tonal interference. We show that the degradation varies with the central frequency of the interference and demonstrate that relatively weak spurious tones can compromise the performance of a DAB receiver. We provide specific evaluations of the severity of the above effect for all possible DAB systems parameterizations and evaluate the permissible levels of spurious tones in such systems. It is shown that for DAB EEP Mode A protection level 4, tonal interference of 14 dB lower than the signal can compromise the receiver performance.

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Section: Receiver Nonlinearitiesmentioning

confidence: 99%

Performance analysis of OFDM and DAB receivers in the presence of spurious tones

Chorti

Brookes

2010

Telecommun Syst

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“…As the number of modern wireless communication systems providing various kinds of services and applications increase, they require more integrated multifunctional antennas for each terminal [1,2]. In pursuit of this system requirement, reconfigurable antennas have been actively developed to be used for the improvement of the system capabilities and for a high degree of radiation control to optimize system performance [3].…”

Section: Introductionmentioning

confidence: 99%

“…This modulation has been proved to be sensitive to impairments such as IQ imbalance, phase noise and nonlinearities [1]. The high peak-to-average power ratio exhibited by OFDM signals makes nonlinear distortion a major system impairment [2]. Important progress has been made in the predistortion techniques to linearize the power amplifier output, implying a more efficient usage of this device [3].…”

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confidence: 99%

Nonlinear effects in lte downlink signals and application of a compensation technique at the receiver side

Allegue‐Martínez

Madero‐Ayora

Crespo‐Cadenas

et al. 2011

Micro & Optical Tech Letters

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bandwidth. Therefore, depending upon a wider AR bandwidth or a higher gain requirement, the h air can be chosen accordingly. Effects of Array Size of Element of SPSNext, we study the effect of array size of element of SPS. Three different stacked array sizes of unit-cell, namely, 2 Â 2, 4 Â 4 and 6 Â 6, are investigated with a fixed height of air gap of 7.5 mm. Figure 7(a) shows the return losses as a function of array sizes. In this variation, we found that resonant frequency is moved to higher frequencies with array size decreases. It is noted that 4 Â 4 array size has the widest bandwidth of 10-dB return-loss. Figure 7(b) shows the comparison of AR and realized gain with array sizes. It is observed that the array size has significant effect on the AR and realized gain. The realized gain is not completely correlated with AR. It is concluded from Figure 7(b) that the widest 3-dB AR bandwidth can be achieved by choosing an array size of 4 Â 4. The realized gain increases with the increase of the array size. The enhancement of the AR can be achieved by selecting the array size of SPS.This parametric study has helped to identify dimensional trends of the most important parameters and facilitated the design of a single-feed CP antenna. CONCLUSIONSThis article demonstrated that the gain, impedance and AR bandwidths of a CP microstrip antenna can be significantly enhanced by stacking with a periodic structure. With the use of a periodic structure superstrate, a wideband and high gain CP-MPA was designed. A key feature of this design is loaded the periodic structure superstrate above the CP patch source. The SPS cannot only be used for increasing the impedance bandwidth, but also the gain and ARBW. The fabricated prototype attained an overlapped bandwidth (return loss ! 10 dB and AR 3 dB) of 10.1% (2.328-2.576 MHz). Average gain of 8 dBi has been achieved across the overlapped bandwidth. The cross-polarization discrimination of 20 dB is observed within the overlapped bandwidth. From measured results, the front-to-back ratio is more than 30 dB. ACKNOWLEDGMENTSThe authors would like to acknowledge the Microwave and Wireless Communication Laboratory at the Chinese University of Hong Kong, for the assistance in the antenna measurement. This work is partially supported by the Faculty of Engineering, King Mongkut's University of Technology North Bangkok. ABSTRACT: This article proposes a nonlinear compensation technique for long-term evolution downlink signals based on the memoryless solidstate power amplifier model, which provides a simple and effective linearization technique at the receiver side, allowing a reduction in the error vector magnitude measured characteristics. The error vector magnitude per subcarrier is analyzed for different appropriate resource blocks allocations in the long-term evolution signal to examine the distortion due to the nonlinear effects produced by a power amplifier in the experimental setup.

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“…11 WiFi and IEEE 802. 16 WiMax. It is also used in applications such as digital video and audio broadcasting (DVB and DAB) [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…The high PAPR causes that the high power amplifier at the transmitter end goes into the nonlinear operating region of its input/output characteristic [8]. This introduces IM products and causes BER degradation [9][10][11][12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Analytical performance evaluation of the OFDM systems in the presence of jointly fifth order nonlinearity and phase noise

Madani

Abdipour

Mohammadi

2010

Analog Integr Circ Sig Process

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This paper presents an exact theoretical analysis of the performance degradation in an orthogonal frequency division multiplexing (OFDM) system when the signal including phase noise is passed through a nonlinear circuit such as high power amplifier (HPA). This circuit is modeled as a fifth order memory-less nonlinear polynomial model (5th order MLNPM). The nonlinear model is derived from important electrical parameters such as gain, 1-dB compression and 3rd order intercept point. Theoretical analysis shows that the detected data symbol at the receiver consists of attenuated version of the original transmitted data symbol, common phase error (CPE), intersub-carrier interference (ICI), third and fifth order intermodulation (IM) components. The analytical expressions for intermodulation noise term are derived using combinatorial methods. By use of the derived expressions, a closed-form output signal to noise ratio (SNR), degradation factor (DF) and probability of error can be evaluated theoretically. For verifying the accuracy of our analysis, comparisons between the theoretical and simulated results with electrical parameter of an actual and applicable HPA are presented. The comparisons show that bit error rate (BER) of analytical results is closely match with simulation results for OFDM system using M-QAM modulation.

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On the effects of memoryless nonlinearities on M-QAM and DQPSK OFDM signals

Cited by 17 publications

References 27 publications

Performance analysis of OFDM and DAB receivers in the presence of spurious tones

Performance analysis of OFDM and DAB receivers in the presence of spurious tones

Nonlinear effects in lte downlink signals and application of a compensation technique at the receiver side

Analytical performance evaluation of the OFDM systems in the presence of jointly fifth order nonlinearity and phase noise

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