Cellular/satellite communications system with improved frequency re-use

• US 5,631,898 A
• Filed: 05/16/1995
• Issued: 05/20/1997
• Est. Priority Date: 01/11/1994
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/442,167
• Time in Patent Office: 735 Days
• Field of Search: 370/17, 370/18, 370/58.1, 370/58.2, 370/58.3, 370/75, 370/95.1, 370/95.2, 370/95.3, 370/104.1, 370/110.4, 375/205, 375/208, 375/209, 375/210, 379/58, 379/59, 379/60, 379/63, 455/7, 455/25, 455/11.1, 455/12.1, 455/13.1, 455/13.2, 455/13.3, 340/825.47, 342/367, 342/368, 342/373, 342/377
• US Class Current: 370/203
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 25/007 using two or more primary active elements in the focal region of a focusing device for operation on different wavebands H01Q5/22
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04B 7/2041 Spot beam multiple access
• CPC Class Codes: H04B 7/2046 SS-TDMA, TDMA satellite switching
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/021 Estimation of channel covariance
• CPC Class Codes: H04L 25/03203 Trellis search techniques
• CPC Class Codes: H04L 25/0328 with interference cancellation circuitry adaptations for interference cancellation within a sequence estimator H04L25/03305; interference related aspects of direct sequence spread spectrum H04B1/7097; interference related aspects of frequency hopping spread spectrum H04B1/715; see also H04B1/10
• CPC Class Codes: H04L 25/03299 : with noise-whitening circuitry
• CPC Class Codes: H04L 25/03331 : Arrangements for the joint estimation of multiple sequences
• CPC Class Codes: H04W 16/02 : Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/14 : Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 74/08 : Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 84/025 : with acknowledge back capability
• CPC Class Codes: H04W 84/042 : Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/06 : Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

A radio communication system and method employs matrix processing of received and transmitted signals to minimize co-channel interference. In one embodiment, the system and method transmits signals to a plurality of remote units by: i) correlating a signal received from a new remote unit during random access transmission with a plurality of individual antenna beam element signals to determine a new column of coefficients for a receive matrix; ii) determining a new inverse C-matrix for receiving traffic from the new remote unit based on an old inverse C-matrix and the new column; iii) transforming the new column to a new transmit C-matrix row by scaling relative coefficient phase angles using a ratio of up- to down-link frequencies; iv) determining a new transmit inverse C-matrix based on an old transmit inverse C-matrix and the new transmit C-matrix row; and v) transmitting signals to the remote units using the new transmit inverse C-matrix.

Claims

1. A method for transmitting signals to a plurality of remote units comprising the steps of:

correlating a signal received from a new remote unit during random access transmission with a plurality of individual antenna beam element signals to determine a new column of coefficients for a receive matrix;

determining a new inverse C-matrix for receiving traffic from the new remote unit based on an old inverse C-matrix and the new column;

transforming the new column to a new transmit C-matrix row by scaling relative coefficient phase angles using a ratio of up- to down-link frequencies;

determining a new transmit inverse C-matrix based on an old transmit inverse C-matrix and the new transmit C-matrix row, and

transmitting signals to said remote units using said new transmit inverse C-matrix.

2. The method of claim 1 further comprising the step of:

repeating each of the steps set forth therein when a new mobile unit makes a random access transmission.

3. An apparatus for transmitting signals to a plurality of remote units comprising:

means for correlating a signal received from a new remote unit during random access transmission with a plurality of individual antenna beam element signals to determine a new column of coefficients for a receive matrix;

means for determining a new inverse C-matrix for receiving traffic from the new remote unit based on an old inverse C-matrix and the new column;

means for transforming the new column to a new transmit C-matrix row by scaling relative coefficient phase angles using a ratio of up- to down-link frequencies;

means for determining a new transmit inverse C-matrix based on an old transmit inverse C-matrix and the new transmit C-matrix row, and

means for transmitting signals to said remote units using said new transmit inverse C-matrix.

4. An apparatus for transmitting signals to a plurality of remote units comprising:

a correlator for correlating a signal received from a new remote unit during random access transmission with a plurality of individual antenna beam element signals to determine a new column of coefficients for a receive matrix;

logic for determining a new inverse C-matrix for receiving traffic from the new remote unit based on the old inverse C-matrix and the new column;

logic for transforming the new column to a new transmit C-matrix row by scaling relative coefficient phase angles using a ratio of up- to down-link frequencies;

logic for determining a new transmit inverse C-matrix based on an old transmit inverse C-matrix and the new transmit C-matrix row, and

a transmitter for transmitting signals to said remote units using said new transmit inverse C-matrix.