Communication Systems

Abstract

A transmission method for use in a multi-hop wireless communication system is provided. The method includes, for two apparatuses having overlapping transmission coverage areas, one of the two said apparatuses being an intermediate apparatus, transmitting a first transmission signal from a first one of those apparatuses in a first transmission window of a particular transmission interval and transmitting a second transmission signal from the second one of those apparatuses in a second transmission window of the particular transmission interval but not in said first transmission window, so that a communication apparatus located in the coverage areas of both the first and second apparatuses can receive said first transmission signal substantially without interference from said second transmission signal.

1 . A multi-hop radio communication system comprising:
 a base station apparatus configured to transmit data in a downlink frame;   an intermediate apparatus configured to relay said data received from said base station apparatus to a user equipment; and   said user equipment configured to receive said relayed data, and transmit data in an uplink frame,   wherein said base station apparatus assigns a transmission window within a frequency band which is used by said base station apparatus for transmission in said downlink frame, to said intermediate apparatus and wherein said base station apparatus and said user equipment are prohibited from transmitting radio signals from said base station apparatus and said user equipment in said transmission window.   
     
     
         2 . The multi-hop radio communication system according to  claim 1 , wherein said transmission window is defined by using frequency and time. 
     
     
         3 . The multi-hop radio communication system according to  claim 1 , wherein said transmission window is assigned to said intermediate apparatus in response to a request from said intermediate apparatus to said base station apparatus. 
     
     
         4 . The multi-hop radio communication system according to  claim 1 , wherein said transmission window is used for transmission from said intermediate apparatus to another intermediate apparatus or said user equipment in said downlink frame. 
     
     
         5 . The multi-hop radio communication system according to  claim 1 , wherein said transmission window is used for transmission from said intermediate apparatus to another intermediate apparatus or said base station apparatus in said uplink frame. 
     
     
         6 . A method used in a multi-hop radio communication system, said method comprising:
 transmitting data from a base station apparatus in a downlink frame;   relaying, by an intermediate apparatus, said data received from said base station apparatus to a user equipment; and   receiving, by said user equipment, said relayed data from said intermediate apparatus, and transmitting data in an uplink frame from said user equipment, and   assigning, by said base station apparatus, a transmission window within a frequency band, which frequency band is used by said base station apparatus for transmission in said downlink frame, to said intermediate apparatus, and prohibiting the transmission of radio signals from said base station apparatus and said user equipment in said transmission window.   
     
     
         7 . A base station apparatus used in a multi-hop radio communication system, said base station apparatus comprising:
 a transmitting unit configured to transmit data that is relayed by an intermediate apparatus to a user equipment in a downlink frame and to prohibit transmission of radio signals in a transmission window that is assigned to said intermediate apparatus by said base station apparatus, said transmission window being within a frequency band which is used by said base station apparatus for transmission in said downlink frame.   
     
     
         8 . An intermediate apparatus used in a multi-hop radio communication system, said intermediate apparatus comprising:
 a receiving unit configured to receive data from a base station apparatus in a downlink frame; and   a transmitting unit configured to transmit data to said base station apparatus or a user equipment for relaying in a transmission window that is assigned by said base station apparatus, said transmission window being within a frequency band which is used by said base station apparatus for transmission in said downlink frame, wherein transmission from said base station apparatus and said user equipment is prohibited in said transmission window.   
     
     
         9 . A user equipment used in a multi-hop radio communication system, user equipment comprising:
 a receiving unit configured to receive relayed data from an intermediate apparatus that relays data transmitted from a base station apparatus in a downlink frame; and   a transmitting unit configured to transmit data in an uplink frame and prohibited from transmitting radio signals in a transmission window that is assigned to said intermediate apparatus by said base station apparatus, said transmission window being within a frequency band which is used by said base station apparatus for transmission in said downlink frame.   
     
     
         10 . 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 in a communication direction along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the one or more intermediate apparatuses, and the one or more intermediate apparatuses 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 using a time-frequency format for transmission during a transmission period, with a plurality of transmission windows being provided within the transmission period, each window occupying a different part, said windows being assignable for transmission in the transmission period, the method comprising:
 transmitting a first transmission signal from a first apparatus, corresponding to one of said one or more intermediate apparatuses, in a first transmission window of a particular transmission period; and   transmitting a second transmission signal from a second apparatus, corresponding to said source apparatus or another intermediate apparatus of said one or more intermediate apparatuses, in a second transmission window of the particular transmission period but not in said first transmission window, the first apparatus and the second apparatus having overlapping transmission coverage areas, wherein said intermediate apparatus transmits its own intermediate-apparatus information in said first transmission window.   
     
     
         11 . The transmission method according to  claim 10 , wherein a further intermediate apparatus of said communication system transmits a further signal in said first transmission window. 
     
     
         12 . The transmission method according to  claim 11 , wherein said further intermediate apparatus transmits its own intermediate-apparatus information in said first transmission window.