Patent ID: 7650261
Filing Date: 2010-01-19
Classification: H04B

Abstract:
1. A time-varying multi-path generating apparatus for simulating multi-path fluctuations in radio communications between a transmission point and a receiving point, comprising: a parameter control unit for controlling a plurality of conditions for generating a plurality of propagation paths, the conditions being parameters and data files, a data storage unit for storing the parameters and data files for generating the propagation paths, a random number generating unit for generating and outputting a plurality of random numbers based on a random number parameter provided by the parameter control unit, a propagation path generating unit for generating a plurality of time-varying propagation paths, and a buffer memory unit configured to store the generated time-varying propagation paths, wherein a plurality of time-varying amplitude functions and a plurality of time-varying phase functions are generated based on the parameters and data files for propagation path generation stored in the data storage unit, and the random numbers generated by the random number generating unit, the time-varying amplitude functions are aligned serially in the time domain such that a time-varying shadow amplitude function is obtained, which is repeated N times, where N represents the number of the propagation paths, resulting in N time-varying shadow amplitude functions, the time-varying phase functions are aligned serially in the time domain such that a time-varying shadow phase function is obtained, which is repeated N times, where N represents the number of the propagation paths, resulting in N time-varying shadow phase functions, an initial amplitude, an initial phase, an initial time delay, and an initial arrival direction are generated as the propagation path parameters of a propagation path using random numbers provided by the random number generating unit based on the initial value generation parameters stored in the data storage unit, and the time-varying shadow amplitude functions and the time-varying shadow phase functions are superimposed on the initial amplitude and the initial phase, respectively, for generating a plurality of time-varying propagation paths, wherein, when generating the time varying propagation paths, if a shadowing object is present in the line of sight, a received electric field strength E is given as the summation of E1 that is an electric field strength of a first radio propagation path diffracted by a knife-edge at one edge of said shadowing object and E2 that is an electric field strength of a second radio propagation path that is different from the first propagation path and diffracted by a knife-edge at another opposite edge of said shadowing object, said first radio propagation path starts at the transmission point, does not pass the another edge of said shadowing object, and is diffracted at the one edge of said shadowing object before reaching the receiving point, said second radio propagation path starts at the transmission point, does not pass the one edge of said shadowing object, and is diffracted at the another edge of said shadowing object before reaching the receiving point, and said shadowing object is between the first and second radio propagation paths.