Multi-hop wireless communications system having relay equipments which select signals to forward

• US 7,184,703 B1
• Filed: 06/06/2003
• Issued: 02/27/2007
• Est. Priority Date: 06/06/2003
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Wilson, Fiona, Naden, James M
• Primary Examiner(s): Anderson, Matthew D.
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US10/456,249
• Time in Patent Office: 1,362 Days
• Field of Search: 455/7, 455/8, 455/9, 455/10, 455/11.1, 455 15- 23, 455/522, 375211-215, 370/335, 370/342, 370317-318, 370/323
• US Class Current: 455/10
• CPC Class Codes: H04B 7/15535 Control of relay amplifier gain amplifier gain control in general H03G3/00; gain control reducing self - or loop interference H04B7/15578
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A multi-hop wireless, for example cellular, communications system is provided comprising a source equipment which may be one of a base station or an end user terminal for transmitting signals towards a destination equipment which may be the other of a base station or an end user terminal via at least one relay equipment. The relay equipment receives a plurality of signals transmitted from one or more source equipments of the system and from this plurality of signals selects a signal to relay. In this way the decision about which relays are included in which communication paths in the system is distributed to the relay equipments of the system, thus reducing the signalling overhead as compared with link state protocols which are typically used for routing in such multi-hop systems.

Claims

1. A relay equipment for deployment in a multi-hop wireless communications system for relaying signals from a source equipment towards a destination equipment, wherein the relay equipment receives a plurality of signals transmitted from one or more source equipments and from these selects a signal to relay towards a destination equipment of the selected signal, the relay equipment further comprising a signal processor for measuring the quality of each signal the relay equipment receives on an uplink, comparing the quality measured for each uplink signal to a threshold quality for that uplink signal, forming a candidate set of uplink signals comprising those received uplink signals having a quality above the threshold, measuring the quality of each signal it receives on a downlink, comparing the quality measured for each downlink signal to a downlink threshold quality for that downlink signal, forming a candidate set of downlink signals comprising those received downlink signals having a quality above their thresholds and selecting that uplink signal of the candidate set of uplink signals having the biggest difference between its measured quality and its threshold quality whose corresponding downlink signal is a member of the candidate set of downlink signals wherein the relay equipment relays that selected uplink signal towards a destination equipment of the selected signal.

2. A relay equipment according to claim 1 which is an end user terminal.

3. A relay equipment for deployment in a multi-hop wireless communications system for relaying signals from a source equipment towards a destination equipment, wherein the relay equipment receives a plurality of signals transmitted from one or more source equipments and from these selects a signal to relay towards a destination equipment of the selected signal, the relay equipment further comprising a signal processor for measuring the quality of each signal the relay equipment receives on a downlink, comparing the quality measured for each downlink signal to a threshold quality for that downlink signal, forming a candidate set of downlink signals comprising those received downlink signals having a quality above their associated thresholds, forming a candidate set of uplink signals comprising the signals received by the relay equipment on uplinks which received uplink signals were received with a quality above their threshold and selecting that downlink signal of the candidate set of downlink signals whose corresponding uplink signal which is a member of the candidate set of uplink signals has the biggest difference between its measured quality and its threshold quality and the relay equipment relays the selected downlink signal towards a destination equipment of the selected signal.

4. A relay equipment for deployment in a multi-hop wireless communications system for relaying signals from a source equipment towards a destination equipment, wherein the relay equipment receives a plurality of signals from one or more source equipments, measures the quality of each signal it receives, compares the quality measured for each signal to a threshold quality for that signal, and selects a signal to relay from the signals having a measured quality above the threshold quality, and transmits the selected signal with a gain which is one of proportional to the measured quality of the selected signal and inversely proportional to the measured quality of the selected signal.

5. A method in a multi-hop wireless communications system of relaying a signal from a source equipment towards a destination equipment, comprising the steps of:

such a relay equipment receiving a plurality of signals from one or more source equipments;

measuring the quality of each signal it receives on an uplink;

comparing the quality measured for each uplink signal to a threshold quality for that uplink signal;

forming a candidate set of uplink signals comprising those received uplink signals having a quality above the threshold;

measuring the quality of each signal it receives on a downlink;

comparing the quality measured for each downlink signal to a downlink threshold quality for that downlink signal;

forming a candidate set of downlink signals comprising those received downlink signals having a quality above their thresholds;

selecting that uplink signal of the candidate set of uplink signals having the biggest difference between its measured quality and its threshold quality whose corresponding downlink signal is a member of the candidate set of downlink signals; and

relaying that selected uplink signal towards a destination equipment of the selected signal.

6. A method according to claim 5 comprising the additional step of making the power of the signal transmitted by a source equipment dependent on feedback received from the associated destination equipment.

7. A method in a multi-hop wireless communications system of relaying a signal from a source equipment towards a destination equipment, comprising the steps of:

such a relay equipment receiving a plurality of signals from one or more source equipments;

measuring the quality of each signal it receives on a downlink;

comparing the quality measured for each downlink signal to a threshold quality for that downlink signal;

forming a candidate set of downlink signals comprising those received downlink signals having a quality above the threshold;

forming a candidate set of uplink signals comprising signals received by the relay equipment on uplinks which received uplink signals were received with a quality above their threshold;

selecting that downlink signal of the candidate set of downlink signals whose corresponding uplink signal which is a member of the candidate set of uplink signals has the biggest difference between its measured quality and its threshold quality; and

relaying that selected downlink signal towards a destination equipment of the selected signal.

8. A method in a multi-hog wireless communications system of relaying a signal from a source equipment towards a destination equipment, comprising the steps of:

such a relay equipment receiving a plurality of signals from one or more source equipments;

measuring the quality of each received signal;

comparing the quality measured for each signal to a threshold quality for that signal;

selecting a signal to relay from the signals having a measured quality above the threshold quality; and

transmitting the selected signal with a gain which is one of proportional to the measured quality of the selected signal and inversely proportional to the measured quality of the selected signal.

9. Computer readable media for installation on a relay equipment of a multi-hop wireless communications system for relaying a signal from a source equipment towards a destination equipment, the computer readable media carrying out the steps of:

processing a plurality of signals received by the relay equipment from one or more source equipments; and

selecting from these a signal for the relay equipment to relay towards a destination equipment of the selected signal, the computer readable media further carrying out the steps of;

measuring the quality of each signal received on an uplink by the relay equipment;

comparing the quality measured for each uplink signal to a threshold quality for that uplink signal;

forming a candidate set of uplink signals comprising those received uplink signals having a quality above the threshold;

measuring the quality of each signal it receives on a downlink;

comparing the quality measured for each downlink signal to a downlink threshold quality for that downlink signal;

forming a candidate set of downlink signals comprising those received downlink signals having a quality above their thresholds; and

selecting that uplink signal of the candidate set of uplink signals having the biggest difference between its measured quality and its threshold quality whose corresponding downlink signal is a member of the candidate set of downlink signals.

10. Computer readable media for installation on a relay equipment of a multi-hop wireless communications system for relaying a signal from a source equipment towards a destination equipment, the computer readable media carrying out the steps of:

processing a plurality of signals received by the relay equipment from one or more source equipments; and

selecting from these a signal for the relay equipment to relay towards a destination equipment of the selected signal, the computer readable media further carrying out the steps of;

measuring the quality of each signal the relay equipment receives on a downlink;

comparing the quality measured for each downlink signal to a threshold quality for that downlink signal;

forming a candidate set of downlink signals comprising those received downlink signals having a quality above the threshold;

forming a candidate set of uplink signals comprising signals received by the relay equipment on uplinks which received uplink signals were received with a quality above their threshold;

selecting that downlink signal of the candidate set of downlink signals whose corresponding uplink signal which is a member of the candidate set of uplink signals has the biggest difference between its measured quality and its threshold quality.

11. Computer readable media for installation on a relay equipment of a multi-hop wireless communications system for relaying a signal from a source equipment towards a destination equipment, the computer readable media carrying out the steps of:

measuring the quality of each signal received from a source equipment;

comparing the quality measured for each signal to a threshold quality for that signal;

selecting a signal to relay from the signals having a measured quality above the threshold quality; and

transmitting the selected signal with a gain which is one of proportional to the measured quality of the selected signal and inversely proportional to the measured quality of the selected signal.