In this paper, we propose a novel 4D model-based iterative reconstruction (MBIR) algorithm for low-angle scatter X-ray Diffraction (XRD) that can substantially increase the SNR. Our forward model is based on a Poisson photon counting model that incorporates a spatial point-spread function, detector energy response and energy-dependent attenuation correction. Our prior model uses a Markov random...

We determine the capacity region of a degraded Gaussian relay channel with multiple relay stages. This is done by building an inductive argument based on the single-relay capacity theorem of Cover and El Gamal. We then give an iterative algorithm for determining the optimal power allocation between the transmitter and the relays. We show that in the case when all noise sources have equal power ...

In this paper, Bit Interleaved Coded Modulation systems with Iterative Decoding (BICM-ID) for Multiple Input Multiple Output (MIMO) channel are considered. Based on minimizing pair-wise error probability, a design criterion is proposed to find the optimal multi-dimensional constellation mapping for a MIMO-BICM-ID system. Using the design criterion and employing the Binary Switching Algorithm, s...

A fast algorithm termed the direct iterative search (DE) is proposed to design the optimal phase-only filters (F’OFs) with a high Homer efficiency and high-signal-to-noise ratio ( SNR) . The DIS optimizes the phase and passband of POF in the sense of maximizing the correlation peak of the signal image and minimizing the noise passage. Simulation results show the capability of the DIS for achiev...

In this paper, we propose an optimized delay diversity (ODD) scheme for fading intersymbol interference (ISI) channels. We derive a cost function for optimization of the ODD transmit filters and we provide a steepest descent algorithm for iterative calculation of the filter coefficients. In addition, an upper bound on the cost function is derived and employed to prove the asymptotic optimality ...

* This paper is supported by National Science Foundation of China (69872014) ABSTRACT The performance of widely-used adaptive noise canceling(ANC) deteriorates much when the desired signal is leaked into the reference channel or when there are uncorrelated noises present in the reference channel. This paper proposes a dual-microphone scheme, named Iterative Noise Canceling (INC), to overcome th...

We propose an iterative design algorithm for jointly optimizing source and channel codes. The joint design combines channel-optimized vector quantization (COVQ) for the source code with rate-compatible punctured convolutional (RCPC) coding for the channel code. Our objective is to minimize the average end-to-end distortion. For a given channel SNR and transmission rate, our joint source and cha...

In this paper, it is shown that oversampled A/D conversion methods can be substantially improved by using iterative postprocessing involving linear ltering as well as nonlinear operations. The only condition is that the quantizer produces a so-called convex code, which is the case for the simple and dithered A/D conversion , as well as for n th order single path modulation. The iterative algori...

In this paper, we propose the space-time turbo codes designed over integer ring for BPSK and QPSK modulation. The proposed spacetime turbo codes addeve the full spatial diversity and can be decoded using the iterative binary soft-input sofl-output (SISO) algorithm. The BPSK/QPSK binary rank criterion is used to find the interleavers which guarantee the full spatial diversity. It is shown that t...

The Gaussian approximation has been used to study iterative decoding algorithms of graph-based codes like turbo codes [7, 8] and low-density parity check (LDPC) codes [6]. In this work, the Gaussian approximation is used to describe the turbo decoding algorithm (TDA) as an elegant discrete dynamical system and explicit iterative equations for the evolution of the BER with the decoder phases of ...