Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath...Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath and non-line-of-sight(NLOS) propagation. In this paper, a ranging error correction method is proposed to improve positioning performance. A TOA ranging error model(TREM) is built to provide the prior information for ranging error correction first. The mean value of TREM within a certain interval is used as the ranging error correction value(RECV). As the RECV may be unreasonable sometimes, we adjust it according to the actual positioning situation and then exploit the final RECV to correct ranging data. The experimental results show that the proposed method could well reduce ranging errors and the positioning performance is obviously improved when using corrected ranging data.展开更多
A set of methods for interprocedural analysis is proposed. First, an ap-proach for interprocedural constant propagation is given. Then the concept of constant propagation is extended so as to meet the needs of data de...A set of methods for interprocedural analysis is proposed. First, an ap-proach for interprocedural constant propagation is given. Then the concept of constant propagation is extended so as to meet the needs of data dependence analysis. Besides certain constant, constant range can also be propagated. The related propagating rules are introduced, and an idea for computing Return function is given. This approach can solve almost all interprocedural constant propagation problems with non-recursive calls. Second, a muItiple-version par-allelizing technique is also proposed for alias problem. The work related to this paper has been implemented on a shared-memory parallel computer.展开更多
基金supported in part by Huawei Innovation Research Program(Grant No.YB2013020011)
文摘Wireless technology provides accurate positioning in indoor environments using time of arrival(TOA) based ranging techniques. However, the positioning accuracy is degraded due to the ranging errors caused by multipath and non-line-of-sight(NLOS) propagation. In this paper, a ranging error correction method is proposed to improve positioning performance. A TOA ranging error model(TREM) is built to provide the prior information for ranging error correction first. The mean value of TREM within a certain interval is used as the ranging error correction value(RECV). As the RECV may be unreasonable sometimes, we adjust it according to the actual positioning situation and then exploit the final RECV to correct ranging data. The experimental results show that the proposed method could well reduce ranging errors and the positioning performance is obviously improved when using corrected ranging data.
文摘A set of methods for interprocedural analysis is proposed. First, an ap-proach for interprocedural constant propagation is given. Then the concept of constant propagation is extended so as to meet the needs of data dependence analysis. Besides certain constant, constant range can also be propagated. The related propagating rules are introduced, and an idea for computing Return function is given. This approach can solve almost all interprocedural constant propagation problems with non-recursive calls. Second, a muItiple-version par-allelizing technique is also proposed for alias problem. The work related to this paper has been implemented on a shared-memory parallel computer.
