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For the time-frequency overlapped signals, a low-complexity single-channel blind source separation (SBSS) algorithm is proposed in this paper. The algorithm does not only introduce the Gibbs sampling theory to separate the mixed signals, but also adopts the orthogonal triangle decomposition-M (QRD-M) to reduce the computational complexity. According to analysis and simulation results, we demonstrate that the separation performance of the proposed algorithm is similar to that of the per-survivor processing (PSP) algorithm, while its computational complexity is sharply reduced.

For the interference hidden in the expected multi-carrier signal, this paper proposes a novel detection and recognition algorithm. The algorithm cannot only detect the single-carrier interference (SCI) by the high-order cumulant, but also finds the multi-carrier signal based on spectrum character. Besides, the algorithm can distinguish the modulation types of the SCI. The algorithm does not depend on any prior knowledge and data-aided, which is propitious to practical applications. The analysis and simulation results demonstrate that the proposed algorithm is effective.

Markov Random Field (MRF) based design methodology presents a new approach to establish high noise-immune structure for ultra-low power circuit designs. The MRF design technique is able to significantly improve the reliability and interference tolerance of the logic circuits. The main idea of this methodology is that the circuit has the highest likelihood for correct logic states from the viewpoint of joint probability distribution. At present, the researches of MRF-based circuit designs focus on the circuit structure and noise tolerant performance analysis for ultra-low supply voltage applications. But there is no investigation on the timing performance of MRF-based circuits. In this paper, we simulated different well-known structures of the fundamental MRF-based elements with HSPICE, and measured the corresponding propagation delay and transition time to evaluate the timing performance of circuit. From the measurements, we find that the propagation delay of MRF-based circuits is one order bigger than that of the traditional (complementary metal oxide semiconductor) CMOS circuits, but MRF-based circuits can achieve similar transition time with traditional CMOS circuits.

In Residue Number System-based systems, how to select moduli set and evaluate its performance is an important issue. The objective of this study is to propose a systemic performance evaluation method for RNS based on the properties of moduli set. By abstracting the inherent properties of moduli sets, such as the complexity of arithmetic units, utilization ratio of dynamic range, parallelism and balance between residue channels, this method can provide advices on moduli set selection and carry out performance estimation before circuits implementation. Furthermore, we also propose a new multi-channel moduli set by introducing a new radix component in this paper. Performance analysis and comparison results show that the proposed multi-channel moduli set has better performance of dynamic range utilization ratio, parallelism and balance than that of the commonly used moduli set with the same number of channels.

In the paper, a new time-delay estimation algorithm, which is based on the cyclic auto-correlation function, is proposed for single-channel two mixed OFDM signals without data-aided. In the method, the linear equations on time delay parameters are constructed from different cyclic autocorrelation functions, and the closed-form solutions are obtained by solving the equations without any prior information of fading parameter and shaping filter. Besides, it also analyzes the Cramer-Rao bound of time-delay estimation of mixed OFDM signal, and verifies the effectiveness of the proposed method through computer simulation. The analysis and simulation results show that the proposed algorithms can achieve good blind estimation for the time delay of mixed OFDM signal in a single channel.

The design of high efficient modulo adders is important for the implementation of DSP algorithms based on Residue Number System (RNS). Moduli sets with this form 2n-2k-1 offer many advantages, such as larger dynamic range and excellent balance among the RNS channels. In this paper, a general algorithm and its VLSI implementation structure are proposed for modulo 2n-2k-1 adder. The proposed algorithm is based on the techniques of prefix operation and carries correction, which eliminates the re-computation of carries. And any existing prefix operation structure can be adopted in the proposed structure. Compared with the same modulo adders with different structures, the proposed modulo 2n-2k-1 adder offers better area*delay.