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CV-QKD has drawn many attentions due to the potential to provide high secret key rate and low cost. Error reconciliation is the key module of post processing of a CV-QKD system. In this paper, an improved LDPC-based SEC error reconciliation scheme is proposed. Through the optimization of inner-level decoding and reduction of the iteration rounds of inter–level decoding, the reconciliation can be accelerated...
This work presents cost-effective low-rank techniques for designing robust adaptive beamforming (RAB) algorithms. At first, we introduce an orthogonal Krylov subspace projection mismatch estimation (OKSPME) method, in which a general linear equation is considered in large dimensions which aims to solve for the steering vector mismatch with known information, then we employ the idea of the full orthogonalization...
Lenstra-Lenstra-Lovász (LLL) is an effective lattice reduction algorithm in multi-input-multi-output (MIMO) system. The usage of LLL lattice reduction can significantly improve the performance of zero-forcing and successive interference cancellation decoders in MIMO communications. But for conventional single channel transmission, when the data streams go through poor channel condition, it usually...
The design of a set of beamformers for the multiple-input single-output (MISO) downlink that provides the scheduled users with the quality-of-service (QoS) level that they requested can be quite sensitive to the accuracy of the channel state information (CSI) that is available at the base station. To mitigate that sensitivity, models for the uncertainty in the CSI can be incorporated in the design...
Sparse unmixing is based on the assumption that each mixed pixel in the hyperspectral image can be expressed in the form of linear combinations of a number of pure spectral signatures that are known in advance. Despite the success of sparse unmixing based on the L0 or L1 regularizer, the limitation of this approach on its computational complexity or sparsity affects the efficiency and accuracy. In...
The two-dimensional (2-D) direction-of-arrival (DOA) estimating for non-circular signals in highly real-time situation is addressed. A new algorithm using a single snapshot for 2-D DOA estimating is proposed. Based on the dual parallel uniform linear array (ULA), three equivalent rotationally invariant covariance matrices are constructed using the single snapshot, which are evaluated to generate the...
This work explores beam forming and two-way relaying to alleviate the dual issues of the spectrum congestion and spectrum under-utilization. These problems can be alleviated by the implementation of underlay cognitive radio networks. However, their reliability, capacity or power, and coverage depend on bi-directional or abbreviated as primary-to-secondary or abbreviated as (P2S) and secondary-to-primary...
Robust service can be achieved in error prone Long Term Evolution-Advanced (LTE-A) by dealing with imperfect Channel Quality Information (CQI). CQI is very crucial in evolved Node B (eNodeB) to decide the corresponding modulation and coding scheme in LTE and LTE-A. User Equipment (UE) will measure and estimate the CQI in order to maximize the throughput performance. Adaptive Modulation and Coding...
Root-MUSIC algorithm is a method of DOA estimation based on polynomial rooting. It estimated based on the cost function instead of peak searching, which greatly reduces the computation compared with MUSIC algorithm. However, it came with some other errors. In this letter, we propose a new method based on the the first-order derivative of the cost function and analyze the mean and the MSE of the proposed...
Ordered successive interference cancellation (OSIC) is a well-established detection strategy for multiple-input multiple-output (MIMO) systems. It offers good performance and has an efficient hardware implementation. Typically, the order in which the symbols are detected is based on the channel matrix and the noise statistics. In this paper, a modified ordering scheme that makes use of the information...
Equalization algorithm has a great significance to overcome the inter-symbol interference (ISI) existing in the satellite communication system. But fixed step size (FSS) LMS equalization algorithms and traditional variable step size LMS (VSSLMS) equalization algorithms do not perform well in some aspects such as convergence speed. Therefore, a VSSLMS equalization algorithm based on logarithmic function...
Endpoint detection is a typical classification problem, which means the signal will be divided into two types of speech and background noise. Under the environment with low SNR, in order to better enhance the discrimination of noise and improve the accuracy of speech endpoint detection system, this paper proposes a new type of voice parameter — sub-band energy-entropy-ratio by combining the sub-band...
Voice recognition technology is very important for prevention of identity crimes and cybercrimes because voice contains a lot of personal information. In this research, we propose a voice recognition system which consists of two stages of the feature extraction and identification. In feature extraction, noise directly affects the reason of feature extraction. Therefore, how to effectively remove noise...
This paper proposes a novel distributed power adjustment algorithm for heterogeneous cellular networks, in which a base station adjusts the transmission power based on the signal quality of neighboring base stations. The aim of the proposed algorithm is to achieve a fair resource allocation among its users with minimal information exchange. An important aspect of the proposed algorithm is that channels...
This paper analyzes the spectral efficiency, probability of a lost block and average delay performances of the generic Repetition Redundancy (RR) and Incremental Redundancy (IR) truncated Hybrid-Automat Repeat reQuest (H-ARQ) algorithms on block-faded Rayleigh channels. The analysis presents the derivation of the three performance metrics' expressions, using an intermediate performance metric called...
Toward legitimate delivery of multimedia data in a wireless network, the localization information-based secret key generation algorithm for the network with more than three (m>3) nodes is proposed. Using the star topology network model, the maximum secret key generation rate (MSR) of the proposed algorithm is analytically derived and validated by computer simulation. The relationship between MSR,...
The problem of radar signal detection against unknown or time variable noise background is discussed. Performance characteristics of the cell-averaging constant false alarm rate (CA CFAR) algorithm are considered as applied to detection of a stationary Gaussian signal against a normal noise background. Specifically, the detection probability is analyzed in dependence on the number of the reference...
In this paper, a complex block orthogonal gradient adaptive-based alogrithm is presented. In order to enhance convergence rate, a complex block conjugate normalised orthogonal gradient adaptive algorithm is introduced based on conjugate gradient principle. The orthogonal direction mechanism is used to update the filter coefficients in stead of the negative gradient direction method. Simulation results...
Maximum likelihood algorithm for blind estimation of spreading sequence in direct-sequence spread-spectrum (DSSS) signals is proposed. Although this algorithm has a high computational complexity, it gives the best estimation accuracy and it can determine the lower bound of spreading sequence estimation. Also, for small periods of the spreading sequence it may be used in practical systems. In order...
Due to the tiny wavelength of millimeter waves (mmWave), tens of antennas can be packed into a small area in mmWave transceivers. However, implementing a radio-frequency (RF) chain for each antenna is impractical due to the high cost and power of mixed-signal devices. To reduce the cost and get benefit from the antennas, an analog RF beamformer is implemented using variable gain amplifiers and analog...
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