Communication Systems

Abstract

A transmission method for use in a multi-hop wireless communication system is provided. The system includes a source apparatus, a destination apparatus and one or more intermediate apparatuses. The system has access to at least one predetermined transmission introduction sequence and also having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval. The method for use in this system includes, when transmitting a message with a preamble in a particular transmission interval, transmitting the preamble in a first transmission window of that transmission interval. The method further includes transmitting the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.

1 . A transmission method for use in a multi-hop wireless communication system, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the system having access to at least one predetermined transmission introduction sequence and also having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to at least one of said apparatuses for use in transmission, the method comprising:
 when transmitting a message with a preamble in a particular transmission interval, transmitting the preamble in a first transmission window of that transmission interval; and   transmitting the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.   
   
   
       2 . A transmission method according to  claim 1 , wherein the second transmission window is assigned to the source apparatus for transmission to at least one said intermediate apparatus. 
   
   
       3 . A transmission method according to  claim 1 , wherein the second transmission window is assigned to at least one said intermediate apparatus for transmission to at least one other said intermediate apparatus. 
   
   
       4 . A transmission method according to  claim 1 , wherein the transmission introduction sequence is a preamble-type sequence identifying its transmitting apparatus and providing training information. 
   
   
       5 . A transmission method according to  claim 1 , wherein the transmission introduction sequence is a sequence that is easily distinguished from the preamble, to avoid false detection of the transmission introduction as the preamble. 
   
   
       6 . A transmission method according to  claim 1 , wherein the second transmission window has a fixed transmission frequency bandwidth which occupies the entire said available transmission bandwidth over its entire part of the transmission interval. 
   
   
       7 . A transmission method according to  claim 1 , wherein the second transmission window has a fixed transmission frequency bandwidth which occupies a fraction of said available transmission bandwidth over its part of the transmission interval. 
   
   
       8 . A transmission method according to  claim 1 , wherein a single said transmission introduction sequence is transmitted in said second transmission window. 
   
   
       9 . A transmission method according to  claim 8  wherein said single transmission sequence is transmitted by said source apparatus and at least one said intermediate apparatus and said transmission introduction sequence comprises a spreading code allowing separate identification of said source apparatus and said at least one intermediate apparatus. 
   
   
       10 . A transmission method according to  claim 1 , wherein more than one said transmission introduction sequence is transmitted in said second transmission window. 
   
   
       11 . A transmission method according to  claim 10  wherein said source apparatus and at least one said intermediate apparatus each transmit an individual transmission introduction sequence using an individual allocation of the transmission frequency bandwidth to that apparatus. 
   
   
       12 . A transmission method according to  claim 11 , using a multi-carrier transmission technique, wherein the individual bandwidth allocations are assigned using decimation. 
   
   
       13 . A transmission method according to  claim 1   1 , using a multi-carrier transmission technique, wherein the individual bandwidth allocations are assigned using sub-banding. 
   
   
       14 . A transmission method according to  claim 1 , including transmitting signaling information indicating the existence of the second window. 
   
   
       15 . The transmission method according to  claim 1 , wherein the time-frequency format is a format for a downlink or uplink sub-frame in a time-division-duplex communication system. 
   
   
       16 . The transmission method according to  claim 1 , wherein said system is an OFDM or OFDMA system, and wherein the time-frequency format is a format for an OFDM or OFDMA downlink or uplink sub-frame of an OFDM or OFDMA time-division-duplex frame. 
   
   
       17 . The transmission method according to  claim 1 , wherein each said discrete transmission interval is a sub-frame period. 
   
   
       18 . The transmission method according to  claim 1 , wherein each said transmission window comprises a region in an OFDM or OFDMA frame structure. 
   
   
       19 . The transmission method according to  claim 1 , wherein each said transmission window comprises a zone in an OFDM or OFDMA frame structure. 
   
   
       20 . A multi-hop wireless communication system, the system comprising:
 a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path;   access means operable to access at least one predetermined transmission introduction sequence and to access a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to one of said apparatuses for use in transmission; and   transmission means for, when transmitting a message with a preamble in a particular transmission interval, transmitting the preamble in a first transmission window of that transmission interval, and for transmitting the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.   
   
   
       21 . A network management entity operable to manage a multi-hop wireless communication system, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the network management entity comprising:
 access provision means operable to provide the communication system with access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, including a first window for preamble transmission and a second window other than said first window for transmitting at least one predetermined transmission introduction sequence, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to at least one of said apparatuses for use in transmission; and   transmission introduction sequence allocation means operable to provide at least one said transmission introduction sequence for use by at least one said intermediate apparatus for transmission in said second transmission window of such a transmission interval.   
   
   
       22 . A source apparatus for use in a multi-hop wireless communication system, the system comprising the source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the source apparatus comprising:
 transmission introduction sequence means operable to access or produce at least one predetermined transmission introduction sequence;   format access means to access a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to one of said apparatuses for use in transmission; and   transmission means operable, when transmitting a message with a preamble in a particular transmission interval, to transmit the preamble in a first transmission window of that transmission interval, and to transmit the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.   
   
   
       23 . An intermediate apparatus for use in a multi-hop wireless communication system, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the intermediate apparatus comprising:
 transmission introduction sequence means operable to access or produce at least one predetermined transmission introduction sequence;   format access means operable to access a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to one of said apparatuses for use in transmission; and   transmission means operable, when transmitting a message with a preamble in a particular transmission interval, to transmit the preamble in a first transmission window of that transmission interval, and to transmit the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.   
   
   
       24 . Software embodied in a computer-readable medium and operable, when executed on a computing device of a multi-hop wireless communication system causes the system, to carry out a transmission method, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the system having access to at least one predetermined transmission introduction sequence and also having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a different part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to at least one of said apparatuses for use in transmission, the method comprising:
 when transmitting a message with a preamble in a particular transmission interval, transmitting the preamble in a first transmission window of that transmission interval; and   transmitting the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.