Abstract: A rate-adaptive method of communicating over a multipath wireless communication system uses multiple links such that each end of a link uses multiple transmit and receive antennas. A number of independent streams that are to be transmitted for each link is determined based on an overall system performance measure. In addition, the system may also jointly determine the best modulation, coding, power control, and frequency assignment for each link, based on an overall system performance measure. In OFDM systems, the number of independent streams, as well as the modulation, coding, and power control, may be determined on a tone-by-tone basis based on an overall system performance measure.
Type:
Grant
Filed:
January 31, 2003
Date of Patent:
June 6, 2006
Assignee:
AT&T Corp.
Inventors:
Hui Luo, Nelson Ray Sollenberger, Jack Harriman Winters
Abstract: A cellular network is controlled such that time slots of transmissions from base stations with the same operating frequency are synchronized. Moreover, adjacent base stations using the same frequency are controlled such that, at any given time, they are transmitting different sync words.
Type:
Grant
Filed:
December 22, 1997
Date of Patent:
February 4, 2003
Assignee:
Telefonaktiebolaget LM Ericsson (publ)
Inventors:
Jan Erik Söderkvist, Lars Peter Wahlström