Method of detecting reference symbols for a digital data receiver
US5732114A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1995 |
| Grant date | Mar 24, 1998 |
| Priority date | — |
| Expiry date | Nov 2, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/042
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
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 …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.