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:
Mar. 24, 1998
Filed:
Jan. 22, 1996
Alcatel N.V., Rijswijk, NL;
Abstract
To assign a carrier frequency to different mobile stations in a conventional Space Division Multiple Access (SDMA) radio system, the stations are differentiated according to the direction in space from which they transmit radio signals to a base station. In addition, the distances between the base station and the mobile stations are compared. To prevent interference at the receiving site (base station BTS), according to the invention a carrier frequency (f) is assigned to the different mobile stations (MS1 to MS3) only if the directions in space (.THETA.1 to .THETA.3) are sufficiently different and the receive levels (P1 to P3) of the radio signals are sufficiently equal. To that end, each mobile station (MS1 to MS3) is assigned a guard area, which encompasses at least a preselected solid angle (lobe width w) and at most a preselected level space (dynamic range S). Any further mobile station wanting a radio link with the base station on the same carrier frequency (f) must be located in a permissible zone (Z) between the guard areas, which comprises a level range (zP) that is common to all preceding mobile stations. A further guard area is defined with each further connection, and the permissible zone (Z) is determined anew. The full capacity of the carrier frequency (f) is only attained when the permissible zone (Z) becomes so small that it no longer comprises sufficient space for the solid angle (w).