Method And Apparatus For Interference Suppression In Orthogonal Frequency Division Multiplexed (OFDM) Wireless Communication Systems

• US 20120134435A1
• Filed: 10/07/2011
• Published: 05/31/2012
• Est. Priority Date: 06/30/1998
• Status: Active Grant

• Current Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Original Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Inventors: Kapoor, Samir, Marchok, Daniel J.
• Granted Patent: US 8,934,457 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method and apparatus for interference suppression in wireless communication systems, especially Orthogonal Frequency Division Multiplexed (OFDM) systems, is presented. The array apparatus includes a two-tier adaptive array system, which provides for both spatial diversity and beamforming at the uplink The adaptive array and includes sub-arrays spaced at a distance sufficient to provide spatial diversity and support beamforming or scanning A Direction of Arrival (DOA) of signals impinging upon the array can be calculated by comparing signals from sub-array elements. Each sub-array can be filtered or beamformed to provide high gain to desired signals received from the DOA (which may be a multipath signal) while simultaneously dampening-out undesired signals, such as co-channel interference (CCI) in the frequency band of operation. The DOA is also used for allocating frequency bins for data signals, such as in an OFDM system, to provide weighted guidelines for bin allocation to maximize received signal power.

Claims

1. In a multi-point communications system having a receiver and transmitter disposed at a primary site for communication with a plurality of remote units disposed at respective secondary sites, an antenna comprising:

multiple elements for receiving communications signals over a carrier frequency from a plurality of remote units, said elements being partitioned into groups disposed remote from one another by at least a predetermined minimum group spacing sufficient to obtain spatial diversity, each group containing at least one element, at least one group including multiple elements located proximate to one another and no further apart than a predetermined maximum element spacing to facilitate spatial filtering.