US 2011/0255394 A1 · System and Method for SSS Detection Under Carrier Frequency Offset in an Orthogonal Frequency-Division Multiple Access Downlink Channel

Abstract

A system and method for SSS detection under carrier frequency offset in an orthogonal frequency-division multiple access (OFDMA) downlink channel. A processor receives a signal sample that includes a transmission on a primary synchronization signal (PSS) and a transmission on a one secondary synchronization signal (SSS). The processor determines a correlation “P” of a first symbol transmitted in the PSS of the signal sample to a first known symbol at each time “t” of time increments k of the signal sample and a correlation “S” of a second symbol transmitted in the a SSS to a second known symbol at each time t-.5/7msecs. The processor receives a candidate phase rotation of θi from a set of “i” candidates and determines a correlation “Cmax” over the time increments k representing a maximum amplitude of a combined correlation of S and P, with P rotated by θi. The processor determines the cell identifier from the first and second known symbols that produced S and P of C max and an estimation of the frequency offset between a transmitter of the signal sample and a receiver of the signal sample.

Claims16

Dependent claims

A method for obtaining a cell identifier in an orthogonal frequency-division multiple access (OFDMA) transmission comprising:

a processor receiving a signal sample, wherein the signal sample comprises a transmission on a primary synchronization channel (PSS) and a transmission on a one secondary synchronization channel (SSS);
the processor determining a correlation “P” of a first symbol transmitted in the PSS of the signal sample to a first known symbol at each time “t” of time increments k of the signal sample, wherein P is a complex number;
the processor determining a correlation “S” of a second symbol transmitted in the a SSS to a second known symbol at each time t-0.5/7 msecs, wherein S is a complex number;
the processor receiving a candidate phase rotation of θi from a set of “i” candidates;
the processor determining a correlation “Cmax” over the time increments k,
wherein C max is a complex number and
C


max
=
max
i

{
abs

(
P
*
exp

(
j
*
θ
i
)
+
S
)
}
;

and
wherein C max represents a maximum amplitude of a combined correlation of S and P, with P rotated by θi, and
the processor determining the cell identifier from the first and second known symbols that produced S and P of C max.

34 more elements

A method for obtaining a cell identifier in an orthogonal frequency-division multiple access (OFDMA) transmission comprising:

a processor receiving a signal sample, wherein the signal sample comprises “R” transmissions on a primary synchronization signal (PSS) and “R” transmissions on a one secondary synchronization signal(SSS), where R is greater than or equal to two;
the processor determining a correlation “P” of a first symbol transmitted at each of the R transmissions of the PSS of the signal sample to a first known symbol at each time “t” of time increments k of the signal sample, wherein P is a complex number;
the processor determining a correlation “S” of a second symbol transmitted in each of the R transmissions of the SSS of the signal sample to a second known symbol at each time t-0.5/7 msecs, wherein S is a complex number;
the processor receiving a candidate phase rotation of θi from a set of “i” candidates;
the processor determining a correlation “Ci” over the time increments k for each of the R transmissions of PSS and SSS in the signal sample at each of the candidate phase rotations i, wherein Ci is a complex number and
Ci=Abs(P1*exp(j*θi)+S1)+ . . . ABS(PR*exp(j*θi)+SR);
the processor determining a correlation Cmax, where
C


max
=
max
i
=
1
i

{
C
i
}
the processor determining the cell identifier from the first and second known symbols that produced S and P of C max.

20 more elements

A method for obtaining a cell identifier in an orthogonal frequency-division multiple access (OFDMA) transmission comprising:

a processor receiving a signal sample, wherein the signal sample comprises “R” transmissions on a primary synchronization channel (PSS) and “R” transmissions on a one secondary synchronization channel (SSS), where R is greater than or equal to two;
the processor determining a correlation “P” of a first symbol transmitted at each of the R transmissions of the PSS of the signal sample to a first known symbol at each time “t” of time increments k of the signal sample, wherein P is a complex number;
the processor determining a correlation “S” of a second symbol transmitted in each of the R transmissions of the SSS of the signal sample to a second known symbol at each time t-0.5/7 msecs, wherein S is a complex number;
the processor receiving a candidate phase rotation of θi from a set of “i” candidates;
the processor determining a correlation “Ci” over the time increments k for each of the R transmissions of PSS and SSS in the signal sample at each of the candidate phase rotations i, wherein Ci is a complex number and
C
i
=

{
(
P
1
*
exp

(
jθ
i
)
+
S
1
)
*
conj

(
P
1
*
exp

(
jθ
i
)
+
S
1
)
+
…
+
(
P
R
*
exp

(
jθ
i
)
+
S
R
)
*
conj

(
P
R
*
exp

(
jθ
i
)
+
S
R
)
}
the processor determining a correlation Cmax, where
C


max
=
max
i
=
1
i

{
C
i
}
the processor determining the cell identifier from the first and second known symbols that produced S and P of C max.

90 more elements

A method for obtaining a cell identifier in an orthogonal frequency-division multiple access (OFDMA) transmission comprising:

a processor receiving a signal sample, wherein the signal sample comprises a transmission on a primary synchronization signal (PSS) and a transmission on a one secondary synchronization signal (SSS);
the processor determining a correlation of two equal segments Pa and Pb of a first symbol transmitted in the PSS of the signal sample to a corresponding segment of a first known symbol at times “ta” and “tb” respectively of time increments k of the signal sample, wherein Pa and Pb are complex numbers;
the processor determining a correlation of two equal segments Sa and Sb of a of a second symbol transmitted in the a SSS to a corresponding segment of a second known symbol at h time ta-0.5/7 msecs and tb-0.5/7 msecs, wherein Sa and Sb are complex numbers;
the processor receiving a candidate phase rotation of θi from a set of “i” candidates;
the processor determining a correlation “Cmax” over the time increments k,
wherein C max is a complex number and
C
=
max
i


{
abs

(
Pb
*
exp

(
j
*
3

θ
i
)
+
P


a
*
exp

(
j
*
2

θ
i
)
+
Sb
*
exp

(
j
*
θ
i
)
+
Sa
)
}
;
and
wherein C max represents a maximum amplitude of a combined correlation of segments Sa, Sb, Pa and Pb, with P rotated by a multiple of θi, and
the processor determining the cell identifier from the first and second known symbols that produced C max.

60 more elements

Dependencies are inferred from the claim text.

System and Method for SSS Detection Under Carrier Frequency Offset in an Orthogonal Frequency-Division Multiple Access Downlink Channel

Life of this patent

System and Method for SSS Detection Under Carrier Frequency Offset in an Orthogonal Frequency-Division Multiple Access Downlink Channel

Life of this patent

Abstract

Claims16