METHOD AND SYSTEM FOR DIVERSITY USING ORTHOGONAL FREQUENCY/DIVISION MULTIPLEXING

• US 20110013678A1
• Filed: 05/26/2010
• Published: 01/20/2011
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: SMITH, Adrian, EARNSHAW, Mark, STEER, David, LI, Xiao-Dong, AU, Kelvin Kar-Kin, NOVAK, Robert
• Granted Patent: US 8,320,840 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: H04B 7/18534 for enhancing link reliablility, e.g. satellites diversity
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time

Abstract

A method and system for achieving a link budget improvement in a diverse OFDM radio system by addressing the timing misalignment issue that can occur due to the differences in propagation time in signals between mobile stations and Radio Access Nodes. Timing misalignment is shared or split between the primary path to a primary Radio Access Node and a diverse path to a diverse Radio Access Node. The relative timing offsets between mobile stations are adjusted, the mobile stations are grouped into zones using a variety of different grouping techniques, and the transmission for each mobile station is scheduled, using one or more of a variety of scheduling techniques.

Claims

1-20. -20. (canceled)

21. A method of transmitting OFDM signals between a plurality of spatially separated transmit antennas and at least one receive antenna, the method comprising:

determining relative timing differential values for the plurality of transmit antennas when the transmit antennas transmit OFDM signals to the at least one receive antenna via at least one diverse path, wherein the relative timing differential values result in a timing misalignment; and

resolving the timing misalignment by allocating the relative timing differential values among the one or more diverse paths.

31. An OFDM transceiver comprising:

a timing differential component operable to determine relative timing differential values for a plurality of spatially separated transmit antennas when the transmit antennas transmit OFDM signals to the OFDM transceiver via at least one diverse path; and

a timing misalignment resolution component operable to allocate the relative timing differential values among the at least one diverse path.