Subrahmanyam Mula

Vinay Chakravarthi Gogineni, Subrahmanyam Mula

This paper introduces a novel constraint adaptive filtering algorithm based on a relative logarithmic cost function which is termed as Constrained Least Mean Logarithmic Square (CLMLS). The proposed CLMLS algorithm elegantly adjusts the cost function based on the amount of error thereby achieves better performance compared to the conventional Constrained LMS (CLMS) algorithm. With no assumption on input, the mean square stability analysis of the proposed CLMLS algorithm is presented using the energy conservation approach. The analytical expressions for the transient and steady state MSD are derived and these analytical results are validated through extensive simulations. The proposed CLMLS algorithm is extended to the sparse case by incorporating the $\ell_1$-norm penalty into the CLMLS cost function. detailed Simulations confirms the superiority of the sparse CLMLS over the state-of-the-art.

Vinay Chakravarthi Gogineni, Subrahmanyam Mula

In this paper, we present the convergence analysis of proportionate-type least mean square (Pt-LMS) algorithm that identifies the sparse system effectively and more suitable for real time VLSI applications. Both first and second order convergence analysis of Pt-LMS algorithm is studied. Optimum convergence behavior of Pt-LMS algorithm is studied from the second order convergence analysis provided in this paper. Simulation results were conducted to verify the analytical results.

Vinay Chakravarthi Gogineni, Subrahmanyam Mula

An improved proportionate adaptive filter based on the Maximum Correntropy Criterion (IP-MCC) is proposed for identifying the system with variable sparsity in an impulsive noise environment. Utilization of MCC mitigates the effect of impulse noise while the improved proportionate concepts exploit the underlying system sparsity to improve the convergence rate. Performance analysis of the proposed IP-MCC is carried out in the steady state and our analysis reveals that the steady state Excess Mean Square Error (EMSE) of the proposed IP-MCC filter is similar to the MCC filter. The proposed IP-MCC algorithm outperforms the state of the art algorithms and requires much less computational effort. The claims made are validated through exhaustive simulation studies using the correlated input.

B. K. N. Srinivasarao, Vinay Chakravarthi Gogineni, Subrahmanyam Mula et al.

This paper presents a new VLSI friendly framework for scalable video coding based on Compressed Sensing (CS). It achieves scalability through 3-Dimensional Discrete Wavelet Transform (3-D DWT) and better compression ratio by exploiting the inherent sparsity of the high-frequency wavelet sub-bands through CS. By using 3-D DWT and a proposed adaptive measurement scheme called AMS at the encoder, one can succeed in improving the compression ratio and reducing the complexity of the decoder. The proposed video codec uses only 7% of the total number of multipliers needed in a conventional CS-based video coding system. A codebook of Bernoulli matrices with different sizes corresponding to the predefined sparsity levels is maintained at both the encoder and the decoder. Based on the calculated l0-norm of the input vector, one of the sixteen possible Bernoulli matrices will be selected for taking the CS measurements and its index will be transmitted along with the measurements. Based on this index, the corresponding Bernoulli matrix has been used in CS reconstruction algorithm to get back the high-frequency wavelet sub-bands at the decoder. At the decoder, a new Enhanced Approximate Message Passing (EAMP) algorithm has been proposed to reconstruct the wavelet coefficients and apply the inverse wavelet transform for restoring back the video frames. Simulation results have established the superiority of the proposed framework over the existing schemes and have increased its suitability for VLSI implementation. Moreover, the coded video is found to be scalable with an increase in a number of levels of wavelet decomposition.