首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 54 毫秒
1.
In this paper, a new primal-dual interior-point algorithm for convex quadratic optimization (CQO) based on a kernel function is presented. The proposed function has some properties that are easy for checking. These properties enable us to improve the polynomial complexity bound of a large-update interior-point method (IPM) to O (√nlognlogn/ε), which is the currently best known polynomial complexity bound for the algorithm with the large-update method. Numerical tests were conducted to investigate the behavior of the algorithm with different parameters p, q and θ, where p is the growth degree parameter, q is the barrier degree of the kernel function and θ is the barrier update parameter.  相似文献   

2.
The dominant error source of mobile terminal location in wireless sensor networks (WSNs) is the non-line-of-sight (NLOS) propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagation error, residual test (RT) is an efficient one, however with high computational complexity (CC). An improved algorithm that memorizes the light of sight (LOS) range measurements (RMs) identified memorize LOS range measurements identified residual test (MLSI-RT) is presented in this paper to addre...  相似文献   

3.
Motion estimation is an important part of the MPEG-4 encoder, due to its significant impact on the bit rate and the output quality of the encoder sequence. Unfortunately this feature takes a significant part of the encoding time especially when the straightforward full search(FS) algorithm is used. In this paper, a new algo-rithm named diamond block based gradient descent search (DBBGDS) algorithm, which is significantly faster than FS and gives similar quality of the output sequence, is proposed. At the same time, some other algo-rithms, such as three step search (TSS), improved three step search (ITSS), new three step search (NTSS),four step search (4SS) , cellular search (CS) , diamond search (DS) and block based gradient descent search (BBGDS) , are adopted and compared with DBBGDS. As the experimental results show, DBBGDS has its own advantages. Although DS has been adopted by the MPEG-4 VM, its output sequence quality is worse than that of the proposed algorithm while its complexity is similar to the proposed one. Compared with BBGDS, the proposed algorithm can achieve a better output quality.  相似文献   

4.
基于Clenshaw递归公式以及离散余弦自身的对称性提出任意长离散余弦变换(DCT)的一种并行递归快速算法,给出了算法的滤波器实现结构;与现有的其它递归算法进行了计算复杂度的比较分析,结果表明我们的算法运算量大大减少且计算的滤波器结构使算法非常适合大规模集成电路(VLSI)的实现.  相似文献   

5.
INTRODUCTION The demand for mobile communication services is increasing at a rapid pace throughout the globe. The increasing demand for mobile communication ser- vices in a limited RF spectrum motivates the need for better techniques to improve spectrum utilization. Smart antenna system was adopted by ITU for the IMT-2000 or the Third Generation (3G) wireless networks due to its capability to improve channel capacity and interference suppression. A smart an- tenna system combines mult…  相似文献   

6.
In this letter, we present a modified vector-perturbation precoding scheme for the multiple-input multiple-output broadcast channel, where a perturbation vector is chosen to take into account both the instantaneous power and the instantaneous peak power of the transmitted signal. This perturbation vector is obtained by using the closest point search, with the aid of the lattice-reduction algorithm. Simulation results show that the proposed scheme yields a tradeoff among power efficiency, peak-to-average power ratio reduction, and complexity.  相似文献   

7.
Calculating the current distribution in circular loop scatterers commonly involves complicated computation. In this paper, based on the theory of Maxwellian circuits (MC), we propose a fast algorithm by solving a wave equation with constant parameters corresponding to the circular loop. Our method prodeces similar results compared to the methods using method of moments (MoM) with lower computational complexity. It is effective when there are parallel multiple circular loop scatterers. Experimental results show accuracy of the method.  相似文献   

8.
付翔  张小飞 《滁州学院学报》2012,14(2):39-41,44
多输入多输出(Multiple-Input Multiple-Output:MIMO)雷达利用多天线发射互相正交的信号,可以实现灵活的发射分集设计,具有高分辨率的空间谱估计性能。为降低计算的复杂度,提升信噪比高时信号的性能,文章基于MUSIC算法对双基站雷达信号的到达角与发射角作相应估计,结合优化方法和误差准则,对不同参数条件下的该算法作了仿真分析和综合比较。结果证明了该算法的有效性。  相似文献   

9.
INTRODUCTION The vehicle routing problem (VRP), which was first introduced by Dantzig and Ramser (1959), is a well-known combinatorial optimization problem in the field of service operations management and logis- tics. The capacitated vehicle routing problem (CVRP) is an NP-hard problem for simultaneously determining the routes for several vehicles from a central depot to a set of customers, and then return to the depot without exceeding the capacity constraints of each vehicle. In pr…  相似文献   

10.
Variable size motion estimation (ME) and disparity estimation (DE) are employed to select the best coding mode for each macroblock (MB) in the current joint multiview video model (JMVM).This technique achieves the highest possible coding efficiency,but it results in extremely large computation complexity which obstructs the multiview video coding (MVC) from practical application.This paper proposes an adaptive early termination of fast mode decision algorithm for MVC.It makes use of the coding information o...  相似文献   

11.
线性约束凸规划的一个新原-对偶路径-跟踪内点算法   总被引:1,自引:0,他引:1  
In this paper, a primal-dual path-following interior-point algorithm for linearly constrained convex optimization (LCCO) is presented. The algorithm is based on a new technique for finding a class of search directions and the strategy of the central path. At each iteration, only full-Newton steps are used. Finally, the favorable polynomial complexity bound for the algorithm with the small-update method is deserved, namely, O(√nlog n/ε).  相似文献   

12.
The constrained Viterbi algorithm (C-VA) makes use of some prior reliable information to reduce complexity andimprove performance of Viterbi algorithm (VA). However it can only be used in the concatenate code scheme because thedetection result of cyclic redundancy check code (CRC) is exploited to provide reliable information. In this paper, a differentway is proposed to provide reliable information for C-VA, which is possible to be used in simple codec. Known bits were addedto the set partitioning in hierarchical trees (SPIHT) coded image sequence periodically and directly. They were thought to bereliable information for C-VA in the decoder. Experimental results show that the proposed scheme can obtain much bettererror resilient ability compared with conventional VA under the extremely inferior channel condition if the best desired qualityof reconstructed images can be sacrificed.  相似文献   

13.
Interior-point methods (IPMs) for linear optimization (LO) and semidefinite optimization (SDO) have become a hot area in mathematical programming in the last decades. In this paper, a new kernel function with simple algebraic expression is proposed. Based on this kernel function, a primal-dual interior-point methods (IPMs) for semidefinite optimization (SDO) is designed. And the iteration complexity of the algorithm as O(n^3/4 log n/ε) with large-updates is established. The resulting bound is better than the classical kernel function, with its iteration complexity O(n log n/ε) in large-updates case.  相似文献   

14.
A fast motion estimation algorithm for mobile communications   总被引:1,自引:0,他引:1  
The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder's performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware.  相似文献   

15.
1 Introduction 1 With the development of the application of wavelet transform (WT), the speed of wavelet transform as a hot issue has been put forward. Fast algorithms of wavelet transform have been studied by many scholars. The Mallat pyramid algorithm put forward by Mallat, as the earliest one in this category, greatly reduces the arithmetic complexity of WT, and plays an important role in the theoretical research of the theory of wavelets. Since its coming into being, various fast algori…  相似文献   

16.
A polynomial interior-point algorithm is presented for monotone linear complementarity problem (MLCP) based on:a class of kernel functions with the general barrier term, which are called general kernel functions. Under the mild conditions for the barrier term, the complexity bound of algorithm in terms of such kernel function and its derivatives is obtained. The approach is actually an extension of the existing work which only used the specific kernel functions for the MLCP.  相似文献   

17.
介绍了一种基于FPGA的可编程SONET OC-192 10 Gbit/s伪随机序列发生器和比特间插入奇偶校验码BIP-8的误码测试仪.该误码测试仪为并行反馈结构,可生成PRBS序列长度为27-1,210-1,215-1,223-1和231-1,通过SFI-4接口,采用10 Gbit/s收发一体光模块,其工作速率可达10 Gbit/s.在OC-192帧同步调整电路中,采用STM-64/OC192二分查找法的帧同步法,显著提高了帧同步速度并减少了帧同步逻辑的复杂度.该系统可作为一种低成本的测试仪评估OC-192-设备与器件,以取代昂贵的商用PRBS测试仪.  相似文献   

18.
基于粒子群优化算法的无源模拟滤波器优化设计方法容易陷入局部最优,收敛速度慢迭代次数多、运算量大且稳定性不够好。提出果蝇优化算法对滤波器的整个参数空间进行高效并行搜索直到获得最优的参数值,实例仿真表明,采用该方法设计的滤波器在相同的带宽准确度及阻带衰减的情况下,具有更快的运算速度及收敛性能。  相似文献   

19.
INTRODUCTION Orthogonal frequency division multiplexing(OFDM) is generally known as an effective techniquefor high data rates and has been adopted by standardssuch as Digital Audio and Video Broadcasting (DABand DVB) (ETSI, 1994; 1997). OFDM is robustagainst frequency selectivity of a multipath channeland the single-tap equalization can be used to detectthe transmitted symbols if frequency-selective fadingchannels are known. Although, the use of pilot tonesis the most robust way …  相似文献   

20.
Current multi-view video coding (MVC) reference model in joint video team (JVT) does not provide efficient rate control schemes. This paper presents a rate control algorithm for MVC by improving the quadratic rate-distortion (R-D) model. We reasonably allocate bit-rate among views based on the correlation analysisl The proposed algorithm consists of three levels to control the rate bits more accurately, of which the frame layer allocates bits according to the frame complexity and the temporal activity. Extensive experiments show that the proposed algorithm can control the bit rate efficiently.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号