IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0551940
(1995-11-02)
|
우선권정보 |
FR-0013318 (1994-11-07) |
발명자
/ 주소 |
- Thebault Bertrand,FRX
- Sehier Philippe,FRX
|
출원인 / 주소 |
|
대리인 / 주소 |
Sughrue, Mion, Zinn, Macpeak & Seas, PLLC
|
인용정보 |
피인용 횟수 :
15 인용 특허 :
2 |
초록
▼
In a method of detecting reference symbols in a digital data stream constituted by successive frames, each frame contains R reference symbols and I information symbols, and the R reference symbols are uniformly spaced apart in the digital data stream. The received signal is sampled with a period T.s
In a method of detecting reference symbols in a digital data stream constituted by successive frames, each frame contains R reference symbols and I information symbols, and the R reference symbols are uniformly spaced apart in the digital data stream. The received signal is sampled with a period T.sub.e =T.sub.s /N.sub.e, where N.sub.e is an integer not less than 2, and T.sub.s is the symbol time. A cross-correlation is calculated, with each calculated cross-correlation supplying a magnitude I.sub.n equal to: ]EQU1 ] where x.sub.n+dNe represents the sample received at instant n+dN.sub.e, S*.sub.d,k represents the complex conjugate of the reference symbol of index d, k .epsilon. {0, . . . , R-1} and represents frame index, r=R/q, where q is an integer not less than 1. The cross-correlations are summed over M frames so as to form energy levels J.sub.M,d equal to: ]EQU2 ] where m is the frame index, M is the number of sums performed, and d .epsilon. {0, . . . , N.sub.e (R+1)-1}. The method further includes a step of detecting the maximum energy level J.sub.M,D =MAX.sub.d J.sub.M,d, the position D of the maximum energy level corresponding to the positions of the reference symbols in the received frames.
대표청구항
▼
[ We claim:] [1.] A method of detecting reference symbols in a digital data stream constituted by successive frames, each frame containing R reference symbols and I information symbols, said R reference symbols being uniformly spaced apart in said digital data stream, said method comprising the step
[ We claim:] [1.] A method of detecting reference symbols in a digital data stream constituted by successive frames, each frame containing R reference symbols and I information symbols, said R reference symbols being uniformly spaced apart in said digital data stream, said method comprising the steps of:calculating a cross-correlation between said digital data stream and a local reference sequence containing said reference symbols, so as to detect the positions of said R reference symbols in said digital data stream, said digital data stream being sampled with a period T.sub.e =T.sub.s /N.sub.e, where N.sub.e is an integer not less than 2, and T.sub.s is the symbol time, wherein said cross-correlation is calculated every T.sub.e on successive frames, each calculated cross-correlation supplying a magnitude I.sub.n equal to: ]EQU10 ] where x.sub.n+dNe represents the sample received at instant n+dNe, S*.sub.d,k represents the complex conjugate of the reference symbol of index d, k .epsilon. {0, . . . , R-1} and represents the frame index, r=R/q, where q is an integer not less than 1;summing said cross-correlations over M frames so as to form energy levels J.sub.M,d equal to: ]EQU11 ] where m is the frame index, M is the number of sums performed, and where d .epsilon. {0, . . . , N.sub.e (R+1)-1}; anddetecting a maximum energy level J.sub.M,D equal to J.sub.M,D =MAX.sub.d J.sub.M,d, the position D of the maximum energy level corresponding to the positions of said reference symbols in said received frames.
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