Signal processing apparatus, signal transmitting apparatus and receiver
Embodiments of the present disclosure provide a signal processing apparatus, a signal transmitting apparatus and a receiver, which are adapted for a frequency division multiplexing system having a high-order modulation format. A receiver having a high-magnification sampling rate by inserting a pilot signal between neighboring subcarriers at a transmitter side, calculating a laser phase noise according to a phase of the pilot signal at a receiver side, and performing down-sampling and equalization processing after performing carrier phase recovery according to the laser phase noise, so that a laser phase noise having a wide frequency may be accurately compensated, thereby having a relatively powerful carrier phase recovery ability.
1. A signal processing apparatus used for a frequency division multiplexing system, comprising:
a memory that stores a plurality of instructions;
a processor that couples to the memory and causes the signal processing apparatus to:
extract a pilot signal inserted between neighboring subcarriers in a frequency domain in received signals,
calculate a laser phase noise in the frequency division multiplexing system according to a phase of the pilot signal,
perform carrier phase recovery on the received signals according to the received signals and the laser phase noise, and
perform down-sampling and equalization processing on the received signals after performing carrier phase recovery on the received signals,
wherein the frequency division multiplexing system is a dual-polarization frequency division multiplexing system, and the calculating of the laser phase noise in the frequency division multiplexing system according to the phase of the pilot signal comprises:
calculating a pilot component matrix of the received signals in two polarization states according to complex amplitude at frequency points of two pilot signals in the two polarization states,
multiplying time domain signals of the received signals by an inverse matrix of the pilot component matrix, to obtain polarization demultiplexed signals, and
extracting phases of the two pilot signals from the polarization demultiplexed signals, and calculating the laser phase noise according to the phases of the two pilot signals.
2. A receiver, comprising the signal processing apparatus as claimed in claim 1 .
3. The signal processing apparatus according to claim 1 ,
wherein the extracting of the pilot signal inserted between the neighboring subcarriers in the frequency domain in received signals comprises:
determining a bandwidth for filtering according to a frequency interval between two subcarriers neighboring the pilot signal in a frequency domain in transmitting the pilot signal, and filtering the received signals near a frequency point of the pilot signal according to the bandwidth for filtering, to extract the pilot signal.