Integrated cellular communications system

• US 5,073,900 A
• Filed: 03/19/1990
• Issued: 12/17/1991
• Est. Priority Date: 03/19/1990
• Status: Expired due to Term

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: David Desales Otten
• Inventors: Mallinckrodt, Albert J.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/495,497
• Time in Patent Office: 638 Days
• Field of Search: 370/18, 379/59, 379/60, 455/33, 455/53, 455/54
• US Class Current: 370/320
• CPC Class Codes: H04B 7/18517 Transmission equipment in earth stations
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04B 7/18534 for enhancing link reliablility, e.g. satellites diversity
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04B 7/18558 Arrangements for managing communications, i.e. for setting up, maintaining or releasing a call between stations
• CPC Class Codes: H04B 7/2041 Spot beam multiple access
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 5/02 Channels characterised by the type of signal
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A cellular communications system is provided having both surface and satellite nodes which are fully integrated for providing service over large areas. A spread spectrum system is used with code division multiple access (CDMA) employing forward error correction coding (FECC) to enhance the effective gain and selectivity of the system. Multiple beam, relatively high gain antennas are disposed in the satellite nodes to establish the satellite cells, and by coupling the extra gain obtained with FECC to the high gain satellite node antennas, enough gain is created in the satellite part of the system such that a user need only use a small, mobile handset with a non-directional antenna for communications with both ground nodes and satellite nodes. User position information is also available. A digital data interleaving feature reduces fading.

Claims

1. A cellular communications system comprising:

at least one space node having a multiple beam antenna positioned so to establish a first set of cells, each space node including means for transmitting and receiving different predetermined sets of code division multiple access coded, spread spectrum waveforms digitally modulated and incorporating forward error correction coding with the waveforms being located in a predetermined frequency band common to all space nodes;

at least one surface node positioned so to establish a second set of cells, each surface node including means for transmitting and receiving the predetermined sets of code division multiple access coded, spread spectrum waveforms in the predetermined frequency band;

a plurality of user units within the cells, each unit including means for communicating with said at least one space node and with said at least one surface node and being operatively responsive to a predetermined one of the sets of code division multiple access coded waveforms to thereby establish selective communication with at least one of the nodes; and

a network controller operationally connected with said at least one space node and with said at least one surface node to selectively allocate communications with said user units among said space and surface nodes.

2. The cellular communications system of claim 1 further comprising position means for determining which cell a selected user unit is in and for indicating the location of the cell.

3. The cellular communications system of claim 1 further comprising position means for determining the position of a selected user unit by providing a selective polling signal to the user unit from two or more nodes, measuring the response times of the user unit to the polling signals, comparing the response times and determining the position of the user unit based on the comparison.

4. The cellular communications system of claim 1 wherein the user unit comprises level control means for adjusting the output power of the user unit such that the signal received from the user unit by a selected node is substantially equal to a reference level.

5. The cellular communications system of claim 4 wherein the level control means measures the signal received at the user unit from a selected node and compares the level of the received signal to a reference level and adjusts the output power of the user unit based on the comparison.

6. The cellular communications system of claim 1:

wherein the waveforms comprise segments of bits; and

further comprising interleaving means for time-spreading adjacent bits in each segment.

7. The cellular communications system of claim 1 wherein the user unit comprises a hand-held, portable transceiver having a substantially non-directional antenna for communicating with the nodes.

8. The cellular communications system of claim 7 wherein the network controller controls the user unit to communicate with the space node of the cell that the user unit is in or with the surface node of the cell it is in based on a predetermined allocation of communication resources.

9. The cellular communications system of claim 1 wherein the multi-beam antenna of the space node provides beams of relatively narrow beamwidth.

10. The cellular communications system of claim 1 wherein the network controller controls the user unit to communicate with the space node of the cell it is within or with the surface node of the cell it is within.

11. The cellular communications system of claim 10 wherein the network controller controls the user unit to communicate with the space node of the cell that the unit is in or with the surface node of the cell it is in based on the quality of the signal received from the user unit at each such node.

12. The cellular communications system of claim 10 wherein the network controller controls the user unit to communicate with the space node of the cell that the unit is in or with the surface node of the cell it is in based on the location of the party with which the user unit desires to communicate.

13. The cellular communications system of claim 1 wherein the predetermined frequency band is divided into a plurality of sub-bands and communications with each space node are conducted in a first sub-band and communicatuons with each surface node are conducted in a second sub-band.

14. The cellular communications system of claim 1 wherein the user is mobile and may move from cell to cell at random.

15. A cellular communications system comprising:

at least one space node having a multiple beam antenna positioned so to establish a first set of cells, each space node including means for transmitting and receiving different predetermined sets of code division multiple access coded, spread spectrum waveforms digitally modulated and incorporating forward error correction coding with the waveforms being located in a predetermined frequency band common to all space nodes;

at least one surface node positioned so to establish a second set of cells, each surface node including means for transmitting and receiving the predetermined sets of code division multiple access coded, spread spectrum waveforms in the predetermined frequency band;

a plurality of user units within the cells, each user unit comprising a hand-held, portable transceiver having a substantially non-directional antenna and including means for communicating with said at least one space node and with said at least one surface node and being operatively responsive to a predetermined one of the sets of code division multiple access coded waveforms to thereby establish selective communication with at least one of the nodes; and

a network controller operationally connected with said at least one space node and with said at least one surface node to selectively allocate communications with said user units among said space and surface nodes.

16. The cellular communications system of claim 15 wherein each user unit comprises level control means for adjusting the output power of the user unit such that the signal received from the user unit by a selected node is substantially equal to a reference level.

17. A cellular communications system comprising:

at least one space node having a multiple beam antenna positioned so to establish a first set of cells, each space node including means for transmitting and receiving different predetermined sets of code division multiple access coded, spread spectrum waveforms digitally modulated and incorporating forward error correction coding in all cells with the waveforms being located in a predetermined frequency band common to all space nodes;

at least one surface node positioned so to establish a second set of cells, each surface node including means for transmitting and receiving the predetermined sets of code division multiple access coded, spread spectrum waveforms in the predetermined frequency band in all cells;

a plurality of user units within the cells, each user unit comprising a hand-held, portable transceiver having a substantially non-directional antenna and including means for communicating with at least one space node and with said at least one surface node and being operatively responsive to a predetermined one of the sets of code division multiple access coded waveforms to thereby establish selective communication with at least one of the nodes, each user unit comprising level control means for adjusting the output power of the user unit such that the signal received from the user unit by a selected node is substantially equal to a reference level; and

a network controller operationally connected with said at least one space node and with said at least one surface node to selectively allocate communications with said user units among said space and surface nodes.

18. The cellular communications system of claim 17 further comprising position means for determining which cell a selected user unit is in and for indicating the location of the cell.

19. The cellular communications system of claim 17 wherein the network controller controls the user unit to communicate with the space node of the cell that the unit is in or with the surface node of the cell it is in.

20. The cellular communications system of claim 17 wherein the user unit comprises means for indicating to the network controller the user-preferred node for communication.