Adaptive blind source separation using constant modulus criterion and signal mutual information

We address the problem of adaptive blind source separation (BSS) from instantaneous multi-input multi-output (MIMO) channels. It is known that the constant modulus (CM) criterion can be used to extract unknown source signals. However, the existing CM based algorithms normally extract the source signals in a serial manner. Consequently, the accuracy in extracting each source signal, except for the first one, depends on the accuracy of previous source extraction. This estimation error propagation (accumulation) causes severe performance degradation. In this paper, we propose a new adaptive separation algorithm that can separate all source signals simultaneously by directly updating the separation matrix. The superior performance of the new algorithm is demonstrated by simulation examples

Blind equalization of non-irreducible and non-column-reduced channels driven by constant modulus signals

We address the blind equalization of finite-impulse-response (FIR), multiple-input multiple-output (MIMO) channels excited by constant modulus (CM) signals. It is known that the algorithms based on the constant modulus (CM) criterion can equalize an FIR MIMO channel that is irreducible and column-reduced. We show in this paper that the CM property of signals can be exploited to construct a zero-forcing equalizer for a non-irreducible and non-column-reduced channel. We also give a lower bound for the order of the equalizer. Simulation examples demonstrate the proposed result.

Preparation of constant viscosity natural rubber with mercaptan

Constant viscosity natural rubber has been prepared using mercaptan. The accelerated storage tests indicate that the storage hardening phenomenon of natural rubber can be inhibited by mercaptan. The amount of mercaptan (2-mercaptobenzothiazole) of 0.14 phr is sufficient to prepare constant viscosity natural rubber and the storage hardening numbers of constant viscosity NR in both Mooney viscosity and Wallace plasticity are less than 4. The processing properties and anti-oxidative behavior of CV-NR can be improved, although the mechanical properties of vulcanizates decreased slightly as compared to those of natural rubber. The results further support the hypothesis that the abnormal groups in natural rubber molecules are aldehyde groups and are responsible for the hardening of natural rubber.