Patent ID: 8255000

Claim:
A process for computing an estimation of the frequency offset in a receiver for a UMTS communication network said receiver receives the signal transmitted by two antennas and including two Common Pilot CHannels (CPICH), said process involving a pre-processing based on the separation of the two signals by means of the computation of r NoTxd ⁡ [ k ] = r ⁡ [ k ] + r ⁡ [ k + 2 ] = ( 1 + j ) ⁢ ( S 1 ⁡ [ k ] + ( - 1 ) ⌊ k + 1 2 ⌋ ⁢ D 2 ⁡ [ k ] ) + N s ⁡ [ k ] r Txd ⁡ [ k ] = ( - 1 ) ⌊ k + 1 2 ⌋ ⁢ ( r ⁡ [ k ] - r ⁡ [ k + 2 ] ) = ( 1 + j ) ⁢ ( S 2 ⁡ [ k ] + ( - 1 ) ⌊ k + 1 2 ⌋ ⁢ D 1 ⁡ [ k ] ) + ( - 1 ) ⌊ k + 1 2 ⌋ ⁢ N d ⁡ [ k ] Where r[k] is the received signal at the instant k; r NoTxd and r Txd are the result of said pre-processing; where for m=1,2 S m [k]=h m exp( jφ 0 )(exp( jkΦ )+exp( j ( k+ 2)Φ)) D m [2 k]=h m exp( jφ 0 )(exp( jkΦ )−exp( j ( k+ 2)Φ)) N s [k]=n[k]+n[k+ 2] N d [k]=n[k]−n[k+ 2] n[k] corresponding to the noise components in the received signal at instant k h m corresponding to the channel response for antenna m (m=1, 2), j corresponding to the imaginary complex such as j 2 =−1 and Φ=2π Δf T said pre-processing being then followed by an estimation of the frequency offset of the received signal.