The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 2000
Filed:
Oct. 27, 1994
Juha H Rapeli, Oulu, FI;
Nokia Mobile Phones Limited, Espoo, FI;
Abstract
The present invention relates to a method and a simulator for simulating an RF channel between a radio transmitter and a radio receiver located at a far distance from one another, in which radio channel multipath propagation occurs, and with which simulation at least part of the phenomena caused by the multipath propagation to the radio signal, such as delay spread, attenuation and Doppler shift are implemented. As taught by the method, an RF signal (f.sub.in) is moved to a lower frequency (f.sub.IF), and from said lower frequency signal (f.sub.IF) thus produced samples are taken and written in a memory at a predetermined write frequency (f.sub.w). The stored samples are read from the memory after a period of time of the length of the propagation delay (t.sub.Di) of each propagation path (i) to be simulated from the storage in the memory at a read frequency (f.sub.Pi) predetermined for each propagation path (i) to be simulated, said read frequency differing from the write frequency (f.sub.w), when the frequency difference (.DELTA.f.sub.01) of said write frequency (f.sub.w) and the propagation-specific read frequency (f.sub.Ri) represent the Doppler shift of the frequency occurring in each propagation path (i).