Adaptive Communications Methods for Multiple User Packet Radio Wireless Networks

• US 20080181170A1
• Filed: 09/18/2006
• Published: 07/31/2008
• Est. Priority Date: 03/06/2001
• Status: Active Grant

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Bromberg, Matthew C., Branlund, Dale A., Kelly, Phillip L.
• Granted Patent: US 8,254,241 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 1/71052 using decorrelation matrix
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 25/03114 non-adaptive, i.e. not adjustable, manually adjustable, or adjustable only during the reception of special signals
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

An exemplary wireless communication network that includes a base that communicates with remote units located in a cell of the network. A base concatenates information symbols with a preamble corresponding to a destination remote unit. One or more remote units communicating with a base each concatenates information symbols with a preamble corresponding to that remote unit. An adaptive receiver system for a base unit rapidly adapts optimal despreading weights for reproducing information symbols transmitted from multiple remote units. A transmitter system for a base unit concatenates information symbols with a preamble associated with a remote unit in the cell. An adaptive receiver system for a remote unit in a communication network rapidly adapts optimal weights for reproducing a signal transmitted to it by a specific base unit in the network. A transmitter system for a remote unit in a cell of a communication network which concatenates information symbols with preamble associated with the remote unit. A base initiates communication with a desired remote unit by transmitting an initiation codeword in a selected entry slot. One or more remote units each initiates communication with a base by transmitting an initiation codeword associated with the remote unit in a selected entry slot. A remote unit synchronizes in time and frequency to the base using a sequence of synchronization signals transmitted by the base in a number of entry slots.

Claims

1. A base station receiver system for recovering a plurality of data streams from a plurality of signals, each signal transmitted from a corresponding one of a plurality of remote units in a radio communication network, comprising:

a receiver coupled to receive said signals, said receiver forming an input data matrix;

a demultiplexer coupled to receive said input data matrix, said demultiplexer separating said input data matrix into a preamble data matrix and an information data matrix;

a matrix decomposition processor coupled to receive said preamble data matrix and providing a first decomposition matrix and a second decomposition matrix, wherein said first decomposition matrix is substantially orthogonal and said second decomposition matrix is substantially upper triangular;

a detector with an input for said first decomposition matrix and using a set of substantially orthogonal preamble vectors to provide a set of detected preamble correlation vectors, wherein said each detected preamble correlation vector corresponds to one of said plurality of remote units;

a weight vector generator coupled to receive said second decomposition matrix and said detected preamble correlation vectors and providing a set of weight vectors, wherein each of said weight vectors is computed using a corresponding one of said set of detected preamble correlation vectors; and

a despreader coupled to receive said information data matrix and said set of weight vectors and providing a set of despread symbol vectors, wherein each despread symbol vector corresponds to one of said plurality of remote units.