Apparatus and method for detecting channel spacing and system
Embodiments of the present disclosure provide an apparatus and method for detecting channel spacing and a system. The apparatus for detecting channel spacing includes a first estimating unit configured to estimate a frequency offset of a center channel according to a received signal, a second estimating unit configured to estimate a frequency offset of a neighboring channel according to the received signal, and a determining unit configured to determine channel spacing according to the frequency offset of the center channel estimated by the first estimating unit and the frequency offset of the neighboring channel estimated by the second estimating unit. With the embodiments of the present disclosure, estimation accuracy of channel spacing may be ensured, and influence of non-ideal factors on estimation value may be reduced.
1. An apparatus for detecting channel spacing, comprising:
a memory that stores a plurality of instructions; and
a processor coupled to the memory and configured to execute the instructions to:
estimate a frequency offset of a center channel according to a received signal;
estimate a frequency offset of a neighboring channel according to the received signal; and
determine channel spacing according to the frequency offset of the center channel estimated by the first estimating unit and the frequency offset of the neighboring channel estimated by the second estimating unit.
2. The apparatus according to claim 1 , wherein the processor further executes the instructions to:
preprocess the received signal, and
estimating unit estimate the frequency offset of the center channel and the frequency offset of the neighboring channel according to the preprocessed received signal.
3. The apparatus according to claim 1 , wherein the apparatus further comprises:
a filter configured to filter the received signal, and
the processor further executes the instructions to: estimate the frequency offset of the center channel and the frequency offset of the neighboring channel according to the filtered received signal.
4. The apparatus according to claim 3 , wherein the filter:
configured to set a filter bandwidth of the center channel, filter the received signal according to the filter bandwidth of the center channel, and provide the filtered signal to the processor; and
configured to set filter bandwidth of the neighboring channel, filter the received signal according to the filter bandwidth of the neighboring channel, and provide the filtered signal to the processor.
5. The apparatus according to claim 4 , wherein the filter bandwidth of the neighboring channel is set to ensure that information on the neighboring channel is maintained and information on the center channel is removed in a case where the channel spacing or the frequency offset of the neighboring channel or the frequency offset of the center channel change.
6. The apparatus according to claim 1 , wherein the apparatus further comprises:
a synchronizer configured to perform synchronization operations on the received signal, and
the processor further executes the instructions to: estimate the frequency offset of the center channel and the frequency offset of the neighboring channel according to the synchronized received signal.
7. The apparatus according to claim 6 , wherein the synchronizer further:
configured to perform a first synchronization operation on the received signal, where the processor estimates the frequency offset of the center channel according to the synchronized received signal; and
configured to perform a second synchronization operation on the received signal, where the processor estimates the frequency offset of the neighboring channel according to the synchronized received signal.
8. The apparatus according to claim 1 , wherein the processor further executes the instructions to: estimate the frequency offset of the center channel and/or the frequency offset of the neighboring channel according to the following formula:
Δ f =angle(< S n ·S n+k *>)/2π kT s ;
where, S n is complex information on an n-th sampling point, S n+k * is complex conjugate information on an (n+k)-th sampling point, and T s is a sampling period, n, k and n+k are integers which are less than the number of sampling points.
9. The apparatus according to claim 1 , wherein the processor further executes the instructions to: estimate the frequency offset of the center channel and/or the frequency offset of the neighboring channel according to the following formula:
Δ f =angle(< S n ·S n+N *>)/2π NT s Δf =angle(< S n ·S n+k *>)/2π kT s ;
where, S n is complex information on a periodic signal or an n-th symbol of a training sequence, S n+N * is complex conjugate information on an (n+N)-th symbol, T s is a symbol period, and N is the number of symbols of each period, n is an integer which is less than the number of symbols.
10. A method for detecting channel spacing, comprising:
estimating a frequency offset of a center channel according to a received signal;
estimating frequency offset of a neighboring channel according to the received signal; and
determining channel spacing according to the estimated frequency offset of the center channel and the estimated frequency offset of the neighboring channel.