The recursive variance-reduction simulation algorithm for network reliability evaluation

This paper proposes a new formulation of the recursive variance-reduction Monte Carlo estimator of the /spl kappa/ terminal unreliability parameter of communication systems. This formulation allows significant reduction in the simulation execution time, as demonstrated by experimental results.     

A recursive variance-reduction algorithm for estimatingcommunication-network reliability

In evaluating the capacity of a communication network architecture to resist possible faults of some of its components, several reliability metrics are used. This paper considers the 𝒦-terminal unreliability measure. The exact evaluation of this parameter is, in general, very costly since it is in the NP-hard family. An alternative to exact evaluation is to estimate it using Monte Carlo simulation. For highly reliable networks, the crude Monte Carlo technique is prohibitively expensive; thus variance reduction techniques must be used. We propose a recursive variance-reduction Monte-Carlo scheme (RVR-MC) specifically designed for this problem, RVR-MC is recursive, changing the original problem into the unreliability evaluation problem for smaller networks. When all resulting systems are either up or down independently of components state, the process terminates. Simulation results are given for a well-known test topology. The speedups obtained by RVR-MC with respect to crude Monte Carlo are calculated for various values of component unreliability. These results are compared to previously published results for five other methods (bounds, sequential construction, dagger sampling, failure sets, and merge process) showing the value of RVR-MC     

A recursive method for network reliability measures evaluation

A new recursive method for evaluation of reliability measure of the communication networks is given in this paper. The main idea of this method is based on the generation of aggregated networks related to the partitions on subsets of node set. Having found the probabilities of the networks states composing the aggregated network, reliability measures can be obtained by summing up the suitable probabilities of the aggregated networks.     

A recursive algorithm for the error probability evaluation of M-QAM

A general recursive algorithm for the efficient and accurate computation of the bit error rate (BER) of square-shaped M-QAM constellations over additive white Gaussian noise (AWGN) channels is derived. We take advantage of the relationship amongst different square-shaped M-QAM constellations using Gray coded bit mapping     

A new algorithm for network system reliability

In this paper, a new algorithm for reliability quantitative analysis of a network system is presented. It is well known that enumeration of the set of minimal paths for a specified node pair in network is much simpler than enumerating the set of minimal cut-sets. We have also presented a concept-half dual network, which converts the problem enumerating the cut-sets into one of enumeration of the path-sets. With the help of SHARP operation [8] we develop a recursive algorithm for calculating the reliability of a network system, which transforms the network into some subnetworks step by step, which are more simple than the former one. Finally we give a method of approximate calculating.     

一个计算无圈有向网络可靠度的新算法

本文对无圈有向网络的可靠度计算进行了研究。提出了加权有序根树的概念，给出了路径集合的一种特殊排序方法，导出一个计算无圈有向网络可靠度的拓扑公式。在该公式的基础上提出了一个新的计算无圈有向网络可靠度的不交积和算法，算法可以生成简洁的可靠度表达式，从而可以有效地计算无圈有向网络的可靠度。同时验证了算法的有效性。     

A new algorithm for reliability evaluation of three-state device complex networks: Minimal cut-minimal path method

In this paper, we have modified W. J. Ruger's method [W. J. Rueger, Microelectron Reliab. 27, 273–277 (1987)], given a new algorithm to compute the two-terminal reliability of three-state device complex networks. It is a fast, simple method by hand and easily used by computers.     

A new distributed location management algorithm for broadbandpersonal communication networks

We propose an efficient location management algorithm for broadband personal communication networks (PCNs) which reduces the complexity of network signaling and delay due to database access when locating a portable station (PS). Previous works on updating and search algorithms for personal communications have concentrated on the access delay due to signaling network traffic only. But, with the advances in fiber optic technology, it will be possible to provide the capacity of signaling network on the order of several Mbps in broadband PCNs. Thus it may be more important to simplify the signaling procedure and reduce the number of database accesses for mobility management at the cost of some increase of signaling traffic. In the proposed algorithm, we first remove all visitor location registers (VLRs) in order to achieve the simplicity of signaling procedure. Thus, only home databases for mobility management are distributed in a global network, and each database keeps only the current locations of PSs initially registered in its management area. It can solve the problem of requiring an impractically large database in a centralized database structure by distributing home location registers (HLRs) while maintaining the simplicity of mobility management and reducing database loads. This algorithm has a simple signaling procedure, and reduces database operations when compared to hierarchical algorithms as network switching hierarchy increases or relocation and calling rate increase     

A sequential regression algorithm for recursive filters

A sequential regression (s.e.r.) algorithm is derived for recursive or infinite impulse response (i.i.r.) adaptive filters. Results pertaining to using the algorithm in a system-identification experiment are also included.     

A new recursive pseudo least squares algorithm for ARMA filteringand modeling. I

This study is based on the observation that if the bootstrapping is combined with different parameterizations of the ARMA (autoregressive moving average) process, then different linearized problems are obtained for the underlying nonlinear ARMA modeling problem. In this part, a specific parameterization termed the predictor space representation for an ARMA process, which decouples the estimation for the AR and the MA parameters, is used. A vector space formalism for the given data case is then defined, and the least-squares ARMA filtering problem is interpreted in terms of projection operations on some linear spaces. A new projection operator update formula, which is particularly suited for the underlying problem, is then used in conjunction with the vector space formalism to develop a computationally efficient pseudo-least-squares algorithm for ARMA filtering. It is noted that these recursions can be put in the form of a filter structure     

A new recursive pseudo least squares algorithm for ARMA filteringand modeling. II

For pt.I see ibid., vol.40, no.11, p.2766-74 (Nov. 1992). A recursive algorithm for ARMA (autoregressive moving average) filtering has been developed in a companion paper. These recursions are seen to have a lattice-like filter structure. The ARMA parameters, however, are not directly available from the coefficients of this filter. The problem of identification of the ARMA model from the coefficients of this filter is addressed here. Two new update relations for certain pseudoinverses are derived and used to obtain a recursive least squares algorithm for AR parameter estimation. Two methods for the estimation of the MA parameters are also presented. Numerical results demonstrate the usefulness of the proposed algorithms     

A recursive link adaptation algorithm for MIMO systems

An algorithm to adjust the coding/modulation (CM) scheme in a multiple-input multiple-output (MIMO) wireless communication system is proposed and analysed. The CM scheme selected for each transmitter is determined by a recursive procedure at the receiver, taking into account estimated signal-to-noise ratio and the properties of available CM schemes. The algorithm performance was tested with different detection algorithms: pseudo-inverse (PINV), V-BLAST and maximum likelihood (ML).     

一种计算具有不可靠结点分布式计算网络可靠性的算法

提出了几个保持可靠性不变的缩减,结合这些缩减,利用因子分解公式建立了一个计算具有不可靠结点的分布式计算网络分布程序可靠性的有效算法,算法的时间复杂性是O(N·(V+E)),并对一些网络在Pentium 120 计算机上作了计算,结果显示用本文算法计算DPR所产生的N和所用时间比其它算法的要小得多。     

A new optimal algorithm for multipump sources of distributed fiber Raman amplifier

The most important feature of the Raman-gain spectrum is that the peak-gain wavelength only depends on the pump wavelength (fixed shift about 100 nm). Using this feature, a new optimal algorithm for multipump sources of a distributed fiber Raman amplifier is designed. The numerical analysis results show that the optimal algorithm is simple and effective.     

A new algorithm for computing the reliability of complex networks by the cut method

It is well known that computing network reliability is equivalent to computing network unreliability. A fusion of the reliability branching algorithm (RBA) with the path method has given a new method for symbolic reliability analysis. The present paper gives a new method for symbolic unreliability; it is a combination of the RBA with the cut method. The algorithm is simple for computing by hand and has easy execution for the use of computers.     

A new recursive algorithm for calculating end-to-end blockingprobability with an arbitrary fixed nonhierarchical routing

This paper presents a new recursive algorithm for calculating end-to-end blocking probability (EEB) with an arbitrary fixed nonhierarchical routing (AFNR) in a circuit-switched network. The new algorithm improves the worst bound of the computation amount (WBCA) for the EEB of a node pair given by Chan (1980) 2^n-1 times, where n is the number of the loss paths in the path-loss sequence. The amount of its practical computation may be far lower than WBCA, For an extreme case, sequential office-control (SOC) routing, it is proportional to the number of the completion paths from origination node to destination node     

一种基于块回归更新的解扩重扩判决指导新算法

本文提出一种适用于直扩码分多址系统的智能天线处理盲算法，该长时期法利用解扩、重扩信号进行反馈指导，并尽可能充分地利用巳接收的所有数据。可变步长梯度方法的运用使得该算法在减少运算量的同时依然拥有很快的收敛速度和极好的稳态性能，与LS-DRMTA和LS-DRMTCMA算法的仿真比较证明了其优越性。     

Performance of a recursive algorithm for polynomial predistorter design

In this article, based on least square estimation, a recursive algorithm for indirect learning structure predistorter is introduced. Simulation results show that of all polynomial predistorter nonlinear terms, higher-order （higher than 7th-order） nonlinear terms are so minor that they can be omitted in practical predistorter design. So, it is unnecessary to construct predistorter with higher-order polynomials, and the algorithm will always be stable. Further results show that even when 15th-order polynomial model is used, the algorithm is convergent after 10 iterations, and it can improve out-band spectrum of 20 MHz bandwidth signal by 64 dB, with a 1.2×10^11 matrix condition number.     

A recursive algorithm for computing Cramer-Rao-type bounds onestimator covariance

We give a recursive algorithm to calculate submatrices of the Cramer-Rao (CR) matrix bound on the covariance of any unbiased estimator of a vector parameter &thetas;_. Our algorithm computes a sequence of lower bounds that converges monotonically to the CR bound with exponential speed of convergence. The recursive algorithm uses an invertible “splitting matrix” to successively approximate the inverse Fisher information matrix. We present a statistical approach to selecting the splitting matrix based on a “complete-data-incomplete-data” formulation similar to that of the well-known EM parameter estimation algorithm. As a concrete illustration we consider image reconstruction from projections for emission computed tomography     

A robust recursive least squares algorithm

A new algorithm is developed, which guarantees the normalized bias in the weight vector due to persistent and bounded data perturbations to be bounded. Robustness analysis for this algorithm has been presented. An approximate recursive implementation is also proposed. It is termed as the robust recursive least squares (RRLS) algorithm since it resembles the RLS algorithm in its structure and is robust with respect to persistent bounded data perturbation. Simulation results are presented to illustrate the efficacy of the RRLS algorithm