In the transmitting, beamforming, and receiving combing (TBRC) MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the...In the transmitting, beamforming, and receiving combing (TBRC) MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization (USVQ) codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean (USK) codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.展开更多
The Point-In-Polyhedron problem is to check whether a point is inside or outside of a given polyhedron.When a degenerate case is detected,the traditional ray-crossing algorithms avoid the case by selecting a different...The Point-In-Polyhedron problem is to check whether a point is inside or outside of a given polyhedron.When a degenerate case is detected,the traditional ray-crossing algorithms avoid the case by selecting a different ray or erase the case by perturbing input data.This paper introduces a Threshold-Based Ray-Crossing (TBRC) algorithm for solving the Point-In-Polyhedron problem.The TBRC algorithm copes directly with degenerate cases by checking whether to count the face intersecting with the ray.It is worth mentioning that the TBRC algorithm can handle all degeneracies without extra computation and storage.Moreover,we analyze the basic algorithm and examine how to accelerate it.The experimental results show that TBRC algorithm is highly efficient and robust for the Point-In-Polyhedron problem,compared to a classical tetrahedron-based algorithm without pre-processing.展开更多
基金the National Natural Science Foundation of China(60702051)the Hi-Tech Research and Development Program of China(2006AAQ IZ260)and Huawei company.
文摘In the transmitting, beamforming, and receiving combing (TBRC) MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization (USVQ) codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean (USK) codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.
基金the Joint Foundation of Guangdong Province and CAS (No.2009B091300149)
文摘The Point-In-Polyhedron problem is to check whether a point is inside or outside of a given polyhedron.When a degenerate case is detected,the traditional ray-crossing algorithms avoid the case by selecting a different ray or erase the case by perturbing input data.This paper introduces a Threshold-Based Ray-Crossing (TBRC) algorithm for solving the Point-In-Polyhedron problem.The TBRC algorithm copes directly with degenerate cases by checking whether to count the face intersecting with the ray.It is worth mentioning that the TBRC algorithm can handle all degeneracies without extra computation and storage.Moreover,we analyze the basic algorithm and examine how to accelerate it.The experimental results show that TBRC algorithm is highly efficient and robust for the Point-In-Polyhedron problem,compared to a classical tetrahedron-based algorithm without pre-processing.