Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
Method for the frequency correction of multicarrier
signals, characterized in that in a feedback control loop a
first (AFC) and a second (CPEE) process for estimation
and/or correction of the carrier frequency deviation is
performed, wherein the first process (AFC) treats frequency
deviations in the order of several carrier spacings and the
second process (CPEE) treats frequency deviations in the
order of a fraction of the carrier spacing.
Claim 2
Dependent Claim
29 words
Method according to claim 1, characterized in that between the first (AFC) and second (CPEE) process is
switched over in dependance of a threshold value (α f s ).
Claim 3
Dependent Claim
45 words
Method according to claim 1 or 2, characterized in that the first (AFC) and second (CPEE) process are performed
after separation of the various carriers of the multicarrier
signal and the results are used to correct the baseband
signal in front of the carrier separation.
Claim 4
Dependent Claim
84 words
Method according to any of claims 1 to 3, characterized
in that the feedback control loop performs the following
steps: when the first process (AFC) is switched on, the second
process(CPEE) is switched off during a whole block (B1); during the following block (B2) it is switched between the
first process(AFC) and the second process(CPEE); at the end of that block (B2) the second process (CPEE) is
reinitialized; after reinitialization the second process (CPEE) is
switched on and the first process(AFC) is switched off.
Claim 5
Dependent Claim
68 words
Method according to any of claims 1 to 4, characterized
in that the multicarrier signal is an OFDM signal comprising
CAZAC-Sequences, M-Sequences and pilot cells, and in the
first process (AFC) CAZAC-Sequences and M-Sequences are
investigated, which are distributed in the reference symbols
of the OFDM signal, and in the the second process (CPEE) the
frequency deviation is estimated by averaging the phase
variation over the pilot cells.
Claim 6
Dependent Claim
66 words
Apparatus for the frequency correction of multicarrier
signals, characterized in that a feedback control loop
comprises a first (AFC) and a second (CPEE) unit for
estimation and/or correction of the carrier frequency
deviation in the first unit (AFC) treats frequency
deviations in the order of several carrier spacings and the
second unit (CPEE) treats frequency deviations in the order
of a fraction of the carrier spacing.
Claim 7
Dependent Claim
92 words
Apparatus according to claim 6, characterized in that the
feddback control loop further comprises: a multiplier (M) for modulation of the multicarrier
signal; a Fast Fourier Transformation unit (FFT) for separation of
the various carriers of the multicarrier signal, whereby
the signal of the separated carriers is supplied to the
first (AFC) and second (CPEE) unit for estimation and/or
correction of the carrier frequency deviation; a local oscillator (DCO), the output of which depends on
the result of said first (AFC) and second (CPEE) unit and
is fed to the multiplier (M).