Yuehong Shen

Underdetermined Blind Identification for Uniform Linear Array by a New Time---Frequency Method

This paper proposes a novel underdetermined blind identification method with several new single-source points (SSPs) detection criteria for uniform linear array, where the mixing matrix is complex-valued. These new criteria are based on quadratic time–frequency distribution and employed to detect the SSPs so that the complex-valued mixing matrix can be estimated more precisely. To further enhance the estimation accuracy, a modified peak detection method is presented by exploiting the known source number. Finally, the complex-valued mixing matrix can be obtained by performing a clustering algorithm on samples at selected SSPs. One of the outstanding superiorities for the proposed algorithm is that the new criteria are strict enough for the points that are not the SSPs, which ensures the estimation accuracy of the mixing matrix. The other is that the performance of estimation precision is high even in the noisy case. Numerical simulation results verify the superiority of the proposed algorithm over the existing algorithms.

A Novel Method for Complex-Valued Signals in Independent Component Analysis Framework

This paper deals with the separation problem of complex-valued signals in the independent component analysis (ICA) framework, where sources are linearly and instantaneously mixed. Inspired by the recently proposed reference-based contrast criteria based on kurtosis, a new contrast function is put forward by introducing the reference-based scheme to negentropy, based on which a novel fast fixed-point (FastICA) algorithm is proposed. This method is similar in spirit to the classical negentropy-based FastICA algorithm, but differs in the fact that it is much more efficient than the latter in terms of computational speed, which is significantly striking with large number of samples. Furthermore, compared with the kurtosis-based FastICA algorithms, this method is more robust against unexpected outliers, which is particularly obvious when the sample size is small. The local consistent property of this new negentropic contrast function is analyzed in detail, together with the derivation of this novel algorithm presented. Performance analysis and comparison are investigated through computer simulations and realistic experiments, for which a simple wireless communication system with two transmitting and receiving antennas is constructed.

A bias removal blind modulation classification algorithm for MIMO channel

With the development of wireless communication, modulation classification (MC) has wide applications both in military and civilian communication, such as anti-interference, adaptive modulation and spectrum management. This paper proposes a bias removal blind MC algorithm (B-MCA) based on the preprocessing of the mixtures, the bias removal equivariant adaptive separation via independence (EASI) algorithm, the bias cancellation of the estimation signals and the high order cumulants (HOC) based classification algorithm. The advantage of the proposed algorithm B-MCA is that, by considering the actual communication scenarios, B-MCA not only can realize the MC of the mixtures in the multiple-input-multiple-out (MIMO) channel, but also has a good recognition rate in the low signal-to-noise ratio (SNR) case. Simulation results show that B-MCA has good performance of convergence rate and classification accuracy.

Estimation and Cancellation of Nonlinear Companding Noise for Companded Multicarrier Transmission Systems

Nonlinear companding transform (NCT) is an efficient method to reduce the high peak-to-average power ratio (PAPR) of multicarrier transmission systems. However, the introduced companding noise severely restrains the bit-error-rate (BER) performance. In this paper, a general and simple companding noise cancellation (CNC) technique is proposed to mitigate the nonlinear companding noise at the receiver. By exploiting the Bussgang theorem and reconstructing the companding process at the transmitter, the estimated approximate companding noise can be used to refine the received signals. Furthermore, by employing the proposed approach to a typical exponential companding (EC), our results indicate that the proposed scheme can greatly relieve the conventional bottleneck, i.e. the so-called trade-off between the PAPR reduction and BER performance, of NCTs. It shows that for a 512-subcarrier and quadrature phase shift keying modulated orthogonal frequency division multiplexing system, the gap of the signal-to-noise ratio is no more than 0.3 dB at

Efficient Optimization of Reference-Based Negentropy for Noncircular Sources in Complex ICA

{P_e} = 1 \times {10^{ - 5}}

A reduced complexity interference cancellation technique based on matrix decomposition for FTN signaling

Pe=1×10-5 between the ideal performance bound and EC-CNC regardless of the companding degree (

Joint blind estimation of symbol timing and carrier frequency offset for 2×2 MIMO-OFDM system based on cyclostationarity

d=1