constant modulus algorithm (CMA) is widely applied for polarization demultiplexing in coherent optical communication system. However, the singular value problem always plagues CMA. Modified CMA based on polarization d...
详细信息
constant modulus algorithm (CMA) is widely applied for polarization demultiplexing in coherent optical communication system. However, the singular value problem always plagues CMA. Modified CMA based on polarization demultiplexing in Stokes space (SS-PDM) was proposed to avoid the singular value problem in simulation. Here we firstly experimentally demonstrate the modified CMA based on SS-PDM in optical coherent receivers. We conduct experiment of 40-Gbit/s polarization multiplexing (PDM) QPSK to verify this method. The experimental results show that the singularity problem of CMA disappears for Polarization-dependent loss (PDL) of 2.7 dB and 4.8 dB by using the modified CMA and the convergence speed of the modified CMA increases significantly compared with that of conventional CMA.
This paper addresses the issue of high peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM)-based multiple-input multiple-output (MIMO) systems. A PAPR reduction technique is develop...
详细信息
Impulse noise is a major performance degrading factor, as it impairs the communication systems, such as mobile radio system, digital subscriber line system, and power line. Various constant modulus algorithms (CMA) we...
详细信息
ISBN:
(数字)9781728172835
ISBN:
(纸本)9781728172835
Impulse noise is a major performance degrading factor, as it impairs the communication systems, such as mobile radio system, digital subscriber line system, and power line. Various constant modulus algorithms (CMA) were introduced to reduce the average of constantmodulus error between the constantmodulus and the equalizer output power in the impulsive noise environment. However, the existing blind learning methods generate large misadjustment and slow convergence rate in the impulse noise of Multiple Input Multiple Output (MIMO) system. To solve the impulse noise problem, the blind equalization method named Robust Adaptive Autoregressive weighted constant modulus algorithm (RAAWCMA) is introduced in this research work for MIMO system. Due to the feasibility and simplicity of stable convergence property, the proposed Robust Adaptive Autoregressive weighted constant modulus algorithm for blind equalization is utilized to solve the complexity of impulse noise in MIMO system. The proposed blind equalization method increases the performance of equalization by adjusting the weight vector based on the samples of output error. Moreover, the maximum average value obtained by the proposed algorithm is revealed based on the evaluation metrics, like Bit Error Rate, Symbol Error Rate, and Mean Square Error which acquire the values of 0.0005, 0.0005, and 0.0001 with the Rayleigh channel, and 0.0004, 0.0004, and 0.0001 with the Rician channel using six antennas.
Focusing on the problem that tracking performance of constant modulus algorithm(CMA) will decrease dramatically in strong interference environment, a beam-forming method based on constant modulus algorithm combined wi...
详细信息
ISBN:
(纸本)9781538653739
Focusing on the problem that tracking performance of constant modulus algorithm(CMA) will decrease dramatically in strong interference environment, a beam-forming method based on constant modulus algorithm combined with gradient algorithm is proposed. Based on application of smart antenna, the characteristics of this method are analysed. Finally the applicability of combined method is verified by computer simulation with an example of four element uniform linear array.
Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the con...
详细信息
Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the constantmodulus criterion and takes full advantage of the noncircular property of the signal of interest (SOI), significantly increasing the output signal-to interference-plus-noise ratio (SINR), enhancing the convergence speed and decreasing the steady-state misadjustment. Since it requires no known training data, the proposed algorithm saves a large amount of the available spectrum. Theoretical analysis and simulation results are presented to demonstrate its superiority over the conventional linear least mean square-based CMA (L-LMS-CMA), the conventional linear recursive least square-based CMA (L-RLS-CMA), WL-LMS-CMA, WL-RLS-CMA and L-UKF-CMA.
Massive MIMO transmission, whose number of antennas is much larger than the number of user terminals, has been attracted much attention as one of key technologies in next-generation mobile communication system because...
详细信息
Massive MIMO transmission, whose number of antennas is much larger than the number of user terminals, has been attracted much attention as one of key technologies in next-generation mobile communication system because it enables improvement in service area and interference mitigation by simple signal processing. Multi-beam massive MIMO has proposed that utilizes the beam selection with high power in analog part and blind algorithm such as constant modulus algorithm (CMA) which does not need channel state information (CSI) is applied in digital part. Proposed configuration obtains high transmission efficiency. We have evaluated QPSK signals because the CMA basically focuses on the constant amplitude modulation. In this paper, in order to achieve the further higher transmission rate, the amplitude and phase compensation scheme is proposed when using the CMA with amplitude and phase modulation scheme such as QAM. The effectiveness of proposed method is verified by the computer simulation.
It has been proved that the blind equalization using constant modulus algorithm (CMA) is a possible solution for channel inversion in orthogonal frequency division multiplexing/offset quadrature amplitude modulation (...
详细信息
ISBN:
(纸本)9781509020614
It has been proved that the blind equalization using constant modulus algorithm (CMA) is a possible solution for channel inversion in orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM). However, the existing solution does not consider the residual interference that remains after equalization, and which is inherent to this type of modulation. In this paper, we propose to reconsider the value of the dispersion parameter in the update algorithm by taking into account this interference in order to enhance the blind equalization performance. The improvement of the CMA in OFDM/OQAM by means of the proposed change of parameter is demonstrated through both theoretical and numerical results.
作者：
Kanmani, M.Kannan, M.Anna Univ
Dept ECE Jerusalem Coll Engn Madras 600025 Tamil Nadu India Anna Univ
Dept Elect Engn Madras Inst Technol Madras 600025 Tamil Nadu India
Multiple-Input Multiple-Output system plays a major role in the fourth generation wireless systems to provide high data rates. In this paper, a blind channel estimation approach has been proposed for finding the chann...
详细信息
Multiple-Input Multiple-Output system plays a major role in the fourth generation wireless systems to provide high data rates. In this paper, a blind channel estimation approach has been proposed for finding the channel length based on the signals received from the MIMO (Multiple-Input Multiple-Output) transceiver. The resultant MIMO channel length information is utilized for estimation of the channel impulse response of the system. The estimation is used for adaptation of the equalizer weights, based on the proposed constant modulus algorithm which has reduced the fading and multipath propagation resulting from Inter Symbol Interference. The performance of the proposed system has been analyzed in terms of Mean Square Error and Symbol Error Rate for various Signal to Noise Ratio. (C) 2015 Elsevier Ltd. All rights reserved.
constant modulus algorithm (CMA) in dual-polarization optical coherent transmission is revisited for optical access. We introduce a refined CMA, exhibit singularity-free operation up to 5 ps/km0.5 polarization mode di...
详细信息
This paper presents an efficient meta-heuristic algorithm based on electromagnetism-like method, which has been successfully implemented in multiuser detection problems. The contribution revisits blind multiuser detec...
详细信息
This paper presents an efficient meta-heuristic algorithm based on electromagnetism-like method, which has been successfully implemented in multiuser detection problems. The contribution revisits blind multiuser detection for multicarrier code division multiple access systems using a novel combined adaptive step-size constant modulus algorithm (CMA) and electromagnetism-like method scheme. To work around potentially computational intractability and improved the capability of suppressing multiple access interference (MAI) for Multicarrier CDMA System, the proposed scheme exploits heuristics in consideration of both global and local exploration of the step size of the CMA. Simulation results obtained confirm that faster convergence and desirable BER performance with low computational complexity can be achieved with electromagnetism-like method based CMA scheme, compared with the previous step-size CMA scheme, genetic algorithm, and particle swarm optimization with CMA scheme. Copyright (c) 2012 John Wiley & Sons, Ltd.
暂无评论