1results about "Frequency-division multiplexing selection" patented technology

This invention discloses an uplink and downlink wavelength locking method and system for Time Division Frequency Division Multiplexing Passive Optical Network (TFDM-PON), including a downlink wavelength difference estimation and compensation stage; an uplink carrier construction and transmission stage; and an optical line terminal (OLT) side reception and demodulation stage. In the downlink wavelength difference estimation and compensation stage, the frequency offset between the OLT transmitting source and the ONU local laser is estimated through the reception and processing of the downlink coherent optical signal by the optical network unit (ONU), and the local laser frequency is compensated. In the uplink carrier construction and transmission stage, an uplink coherent optical signal with controllable spectrum is generated based on the local laser source locked in the downlink wavelength difference estimation and compensation stage. In the OLT side reception and demodulation stage, the OLT receives the uplink coherent optical signals from each ONU, utilizing the predictability of the uplink optical carrier frequency. This invention provides an uplink and downlink wavelength locking method and system for TFDM-PON, effectively reducing the complexity of digital signal processing on the OLT side and improving the stability, reliability, and scalability of the system in scenarios with multiple ONUs concurrent access.