Transmitting apparatus and method for a digital telecommunication system

Abstract

A transmitting apparatus transmits signals in a digital telecommunication system and a synchronising method is used for synchronizing such signals at a receiving apparatus. The transmitting apparatus prepares for transmission of a reference symbol having at least two repetition patterns, whereby one of the at least two repetition patterns is phase-shifted in relation to the other repetition pattern, and a synchronizing mechanism in the digital telecommunication system uses the reference symbol once received for synchronization. The synchronizing mechanism uses a cross-correlation mechanism to cross-correlate at least one of the two repetition patterns within a correlation window having a predetermined length.

1 . A transmitting apparatus for transmitting a digital signal in a digital telecommunication system, the transmitting apparatus comprising:
 means for preparing a reference symbol comprising a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples; and   means for transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side apparatus,   wherein an end synchronization repetition pattern in said reference symbol is phase-shifted by 180° and said reference symbol comprises a number of said synchronization repetition patterns and said phase-shifted synchronization repetition pattern is positioned after the sequence of said number of synchronization repetition patterns so that the receiver side apparatus can exactly detect a timing of a correlation peak at the end of said reference symbol by performing a cross-correlation of said synchronization repetition patterns.   
     
     
         2 . The transmitting apparatus according to  claim 1 ,
 further comprising adjusting means for increasing the transmission power when transmitting the reference symbol.   
     
     
         3 . A method for transmitting a digital signal in a digital telecommunication system, comprising the steps of
 preparing a reference symbol comprising of a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples,   transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side,   wherein an end synchronization repetition pattern in said reference symbol is phase-shifted by 180° and said reference symbol comprises a number of said synchronization repetition patterns and said phase-shifted synchronization repetition pattern is positioned after the sequence of said number of synchronization repetition patterns so that the receiver side can exactly detect a timing of a correlation peak at the end of said reference symbol by performing a cross-correlation of said synchronization repetition patterns.   
     
     
         4 . The method according to  claim 3 ,
 further comprising the step of increasing the transmission power when transmitting the reference symbol.   
     
     
         5 . A transmitting apparatus for transmitting a digital signal in a digital telecommunication system, the transmitting apparatus comprising:
 means for preparing a reference symbol comprising a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples; and   means for transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side apparatus,   wherein an end synchronization repetition pattern in said reference symbol is phase-shifted by 180° and said reference symbol comprises a number of said synchronization repetition patterns and said phase-shifted synchronization repetition pattern is positioned after the sequence of said number of synchronization repetition patterns so that the receiver side apparatus can perform a synchronization process in accordance with said synchronization repetition patterns and exactly detect a timing of said end of the reference symbol by performing a cross-correlation of said synchronization repetition patterns.   
     
     
         6 . The transmitting apparatus according to  claim 5 ,
 further comprising adjusting means for increasing the transmission power when transmitting the reference symbol.   
     
     
         7 . A method for transmitting a digital signal in a digital telecommunication system, comprising the steps of:
 preparing a reference symbol comprising of a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples; and   transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side,   wherein an end synchronization repetition pattern in said reference symbol is phase-shifted by 180° and said reference symbol comprises a number of said synchronization repetition patterns and said phase-shifted synchronization repetition pattern is positioned after the sequence of said number of synchronization repetition patterns so that the receiver side can perform a synchronization process in accordance with said synchronization repetition patterns and exactly detect a timing of said end of the reference symbol by performing a cross-correlation of said synchronization repetition patterns.   
     
     
         8 . The method according to  claim 7 ,
 further comprising the step of increasing the transmission power when transmitting the reference symbol.   
     
     
         9 . A transmitter device for transmitting OFDM signals to a receiver in an OFDM system, comprising:
 means for preparing a reference symbol comprising a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples;   means for transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side apparatus in said OFDM system; and   means for preparing a reference symbol comprising a plurality of successive repetition patterns, wherein said reference symbol is transmitted from said transmitter device by using multicarriers of said OFDM system and a last repetition pattern of said successive repetition patterns is phase-shifted in relation to the other repetition patterns, and   wherein each of said successive repetition patterns generated by said generating means is composed of the same number of samples, so that said synchronization repetition patterns transmitted to said receiver side apparatus are cross-correlated in said receiver side device in order to perform time and frequency synchronization in said receiver side device.   
     
     
         10 . The transmitter device according to  claim 9 ,
 whereby the last repetition pattern of said successive repetition patterns is phase-shifted by 180° in relation to the other repetition patterns.   
     
     
         11 . The transmitter device according to  claim 9 ,
 further comprising adjusting means for increasing the transmission power when transmitting the reference symbol.   
     
     
         12 . A method for transmitting OFDM signals to a receiver side in an OFDM system, comprising the steps of:
 preparing a reference symbol comprising a sequence of a plurality of synchronization repetition patterns, wherein each repetition pattern contains a predetermined number of samples;   transmitting said reference symbol as a part of said digital signal by using OFDM modulation to a receiver side in said OFDM system; and   preparing a reference symbol comprising a plurality of successive repetition patterns, wherein said reference symbol is transmitted from a transmitter side by using multicarriers of said OFDM system and a last repetition pattern of said successive repetition patterns is phase-shifted in relation to the other repetition patterns,   wherein each of said generated successive repetition patterns is composed of the same number of samples, so that said synchronization repetition patterns transmitted to said receiver side are cross-correlated on said receiver side in order to perform time and frequency synchronization on said receiver side.   
     
     
         13 . The method according to  claim 12 ,
 whereby the last repetition pattern of said successive repetition patterns is phase-shifted by 180° in relation to the other repetition patterns.   
     
     
         14 . The method according to  claim 12 ,
 further comprising the step of increasing the transmission power when transmitting the reference symbol.   
     
     
         15 . A transmitter device for transmitting OFDM signals in an OFDM telecommunication system, the device comprising:
 means for generating said OFDM signals having a reference symbol comprising a plurality of successive repetition patterns, wherein a last repetition pattern of said plurality of successive repetition patterns is phase-shifted in relation to the other repetition patterns; and   means for transmitting said generated OFDM signals including said reference symbol and transmitting data to a receiver side device,   wherein each of said plurality of successive repetition patterns generated by said generating means is composed of the same number of samples respectively so that said repetition patterns transmitted to said receiver side device are cross-correlated in said receiver side device in order to perform time and frequency synchronization in said receiver side device.   
     
     
         16 . The transmitter device according to  claim 15 ,
 whereby the last repetition pattern of said plurality of successive repetition patterns is phase-shifted by 180° in relation to the other repetition patterns.   
     
     
         17 . The transmitter device according to  claim 15 ,
 further comprising adjusting means for increasing the transmission power when transmitting the reference symbol.   
     
     
         18 . A method for transmitting OFDM signals in an OFDM telecommunication system, comprising the steps of:
 generating said OFDM signals having a reference symbol comprising a plurality of successive repetition patterns, wherein a last repetition pattern of said plurality of successive repetition patterns is phase-shifted in relation to the other repetition patterns; and   transmitting said generated OFDM signals including said reference symbol and transmitting data to a receiver side,   wherein each of said generated successive repetition patterns is composed of the same number of samples so that said repetition patterns transmitted to said receiver side are cross-correlated on said receiver side in order to perform time and frequency synchronization on said receiver side.   
     
     
         19 . The method according to  claim 18 , whereby the last repetition pattern of said successive repetition patterns is phase-shifted by 180° in relation to the other repetition patterns. 
     
     
         20 . The method according to  claim 18 , further comprising the step of increasing the transmission power when transmitting the reference symbol.