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. 28, 1996
Filed:
Dec. 07, 1993
Mats E Eriksson, Boden, SE;
Hans L Rinnback, Jarfalla, SE;
Hakan O Djuphammar, Stockholm, SE;
Olov T Edler, Spanga, SE;
Sven E Nilsson, Dallas, TX (US);
Telefonaktiebolaget LM Ericsson, Stockholm, SE;
Abstract
In a base station of a mobile cellular telephone system of the type having time division multiple access (TDMA) channels, a radio frequency test loop is established between a predetermined downlink channel of a base station transmitter and a predetermined uplink channel of a base station receiver. The test loop is in real time, thereby eliminating the time offset of the radio channels used for communications. The radio frequency test loop includes a circuit for transposing the frequency of the carrier signal from the transmitter to a frequency that can be received by the receiver. The signal having the transposed frequency is used in tests for determining values such as bit error rate (BER), transmission signal level, or reception sensitivity.