Communication systems

• US 7,983,151 B2
• Filed: 07/31/2007
• Issued: 07/19/2011
• Est. Priority Date: 10/02/2006
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Zhou, Yuefeng, Hart, Michael John Beems, Vadgama, Sunil Keshavji
• Primary Examiner(s): Wong; Xavier Szewai
• Application Number:
  US12/226,659
• Publication Number:
  US 20090185479A1
• Time in Patent Office: 1,449 Days
• Field of Search: None
• US Class Current: 370/218
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04L 1/1816 with retransmission of the same, encoded, message
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/243 using M+N parallel active paths

Abstract

An uplink transmission method for use in a multi-hop communication system, the system comprising a mobile station (MS), a base station (BS) and one or more relay stations (RS), and the system providing two or more different communication paths extending between the mobile station and the base station, the mobile station being operable to transmit information indirectly to the base station along a series of links forming a first such communication path via one or more of the relay stations and also being operable to transmit information to the base station along one link or a series of links forming a second such communication path; the method comprising transmitting particular information from the mobile station along the first and the second communication paths; and combining the same particular information transmitted along the first and second communication paths in the base station.

Claims

1. An uplink transmission method for use in a multi-hop communication system, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, and the system providing two or more different communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path;

and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

the method comprising

transmitting particular information from the source apparatus along the first communication path via one or more of said intermediate apparatuses to the destination apparatus;

transmitting the same particular information from the source apparatus along the second communication path to the destination apparatus; and

combining the same particular information transmitted along the first and second communication paths in the destination apparatus;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.

2. The method according to claim 1, wherein the second communication path is a direct communication path and the same particular information is transmitted along the second path directly from said source apparatus to said destination apparatus.

3. The method according to claim 1, wherein the second communication path is an indirect communication path via one or more of said intermediate apparatuses and the same particular information is transmitted along the second path from said source apparatus to said destination apparatus via each of these intermediate apparatuses.

4. The method according to claim 1, wherein the system further provides a third such communication path, said source apparatus being configured to transmit the same particular information indirectly to the destination apparatus along a series of links forming the third communication path via one or more of said intermediate apparatuses, the method further comprising

transmitting the same particular information from the source apparatus along the third communication path via each of these intermediate apparatuses to the destination apparatus;

combining the same particular information transmitted along the first, second and third communication paths in the destination apparatus; and

checking the combined information from the first, second and third communication paths for errors.

5. The method according to claim 1, wherein the same particular information is transmitted along both or all, as the case may be, of the said communication paths to said destination apparatus in a discrete time period for uplink transmission only, which is followed by a discrete time period for downlink transmission only.

6. The method according to claim 1, further comprising, before transmission of said particular information, allocating transmission timing in the destination apparatus indicating when the said particular information is to be transmitted along the said communication paths.

7. The method according to claim 1 further comprising checking the combined information from the first and second communication paths for errors.

8. The method according to claim 7, further comprising transmitting an error indication if an error is found and/or transmitting a positive indication if no error is found.

9. The method according to claim 8, wherein the error indication includes a request for retransmission of the particular information.

10. The method according to claim 9, further comprising, if an error indication is transmitted, re-transmitting the particular information along one or more of said communication paths and combining the re-transmission with the previously combined information.

11. The method according to claim 7, further comprising adding an error detection sequence to said particular information before transmission and using the error detection sequence in the destination apparatus to check for errors in the combined information wherein the error detection sequence is preferably a Cyclic Redundancy Check (CRC).

12. The method according to claim 1, further including decoding the encoded information if no errors are detected.

13. The method according to claim 5, wherein the discrete time period for uplink transmission and the discrete time period for downlink transmission are an uplink sub-frame and a downlink sub-frame respectively in a time-division-duplex communication system.

14. The method according to claim 1, wherein said system is an Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) system.

15. The method according to claim 1, wherein said source apparatus is a user terminal or a relay station;

said destination apparatus is a base station, or a relay station; and

the intermediate apparatus or each said intermediate apparatus is a relay station.

16. A multi-hop wireless communication system, the system comprising:

a source apparatus, a destination apparatus and one or more intermediate apparatuses, and the system providing two or more different uplink communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path, and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

transmission means configured to transmit particular information from the source apparatus along the first communication path via one or more of said intermediate apparatuses to the destination apparatus, and to transmit the same particular information from the source apparatus along the second communication path to the destination apparatus; and

combination means configured to combine the same particular information transmitted along the first and second communication paths in the destination apparatus;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.

17. A method in a destination apparatus of a multi-hop communication system, for improving reception reliability, the system comprising a source apparatus, the destination apparatus and one or more intermediate apparatuses, and the system providing two or more different uplink communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path, and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

the method comprising

receiving particular information transmitted from the source apparatus along the first communication path via one or more of said intermediate apparatuses;

receiving the same particular information transmitted from the source apparatus along the second communication path; and

combining the same particular information transmitted along the first and second communication paths;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.

18. A destination apparatus of a multi-hop communication system, the system comprising a source apparatus, the destination apparatus and one or more intermediate apparatuses, and the system providing two or more different uplink communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path, and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

the destination apparatus comprising

receiving means configured to receive particular information transmitted from the source apparatus along the first communication path via one or more of said intermediate apparatuses to the destination apparatus, and to receive the same particular information transmitted from the source apparatus along the second communication path to the destination apparatus; and

combination means configured to combine the same particular information transmitted along the first and second communication paths in the destination apparatus;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.

19. A non-transitory computer-readable medium storing at least one computer program which, when executed on computing devices of a multi-hop wireless communication system, cause the system to carry out an uplink transmission method, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, and the system providing two or more different communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path, and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

the method comprising

transmitting particular information from the source apparatus along the first communication path via one or more of said intermediate apparatuses to the destination apparatus;

transmitting the same particular information from the source apparatus along the second communication path to the destination apparatus;

combining the same particular information transmitted along the first and second communication paths in the destination apparatus;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.

20. A non-transitory computer-readable medium storing a computer program which, when executed on a computing device of a destination apparatus in a communication system, causes the destination apparatus to carry out a method for improving reception reliability, the system comprising a source apparatus, the destination apparatus and one or more intermediate apparatuses, and the system providing two or more different uplink communication paths extending between said source apparatus and said destination apparatus, said source apparatus being configured to transmit information indirectly to the destination apparatus along a series of links forming a first such communication path via one or more of said intermediate apparatuses and also being configured to transmit information to said destination apparatus along one link or a series of links forming a second such communication path, and the intermediate apparatus or each said intermediate apparatus being configured to receive information from a previous apparatus along a path and to transmit the received information to a subsequent apparatus along a path;

the method comprising;

receiving particular information transmitted from the source apparatus along the first communication path via one or more of said intermediate;

receiving the same particular information transmitted from the source apparatus along the second communication path; and

combining the same particular information transmitted along the first and second communication paths;

wherein, before said particular information is transmitted, it is encoded with Hybrid Automatic Repeat Request (HARQ) packet encoding, wherein the transmissions of the same information along both or all of the communication paths, as the case may be, are treated as transmission and re-transmission(s) according to HARQ.