OFDMA baseband clock synchronization
AssigneeShure Acquisition Holdings, Inc.
InventorsMichael Rodriguez, Honghui Xu
Life of this patent
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Abstract
A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.
Claims20
A method for clock synchronization in a wireless audio system comprising:
- receiving a plurality of pilot subcarriers from a wireless transmitter;
- determining a channel estimate for each of the plurality of pilot subcarriers;
- determining one or more channel phase slope values based on the channel estimate for each of the plurality of pilot subcarriers;
- summing the one or more channel phase slope values to generate a channel phase slope;
- determining a timing offset estimate based on the channel phase slope;
- determining a tuning value based on the timing offset estimate;
- modifying a reference oscillator based on the tuning value to generate a modified reference signal;
- and
- controlling a clock based on the modified reference signal.
A wireless audio system, comprising:
- a wireless transmitter configured to transmit a plurality of pilot subcarriers;
- and
- one or more wireless receivers, each configured to:
- receive the plurality of pilot subcarriers;
- determine a timing offset estimate based on the plurality of pilot subcarriers;
- determine a tuning value by applying weighted coefficients to (i) the timing offset estimate and (ii) an integration of previously determined timing offset estimates;
- modify a reference oscillator based on the tuning value to generate a modified reference signal;
- and
- control a clock based on the modified reference signal.
A wireless receiver, comprising:
- an antenna configured to receive a plurality of pilot subcarriers from a wireless transmitter;
- a reference oscillator configured to generate a reference signal;
- and
- circuitry configured to:
- determine a timing offset estimate based on the plurality of pilot subcarriers;
- determine a tuning value by applying weighted coefficients to (i) the timing offset estimate and (ii) an integration of previously determined timing offset estimates;
- modify the reference oscillator based on the tuning value to modify the reference signal and generate a modified reference signal;
- and
- control a clock based on the modified reference signal.
Dependencies are inferred from the claim text.