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.
Claims16
A method for baseband clock synchronization in a wireless microphone system comprising:
- receiving a plurality of pilot subcarriers from an audio transmitter;
- determining a timing offset estimate based on the pilot subcarriers, wherein determining the timing offset estimate comprises:
- determining a channel phase slope based on the plurality of pilot subcarriers, wherein determining the channel phase slope comprises:
- determining the channel estimate for each of the plurality of pilot subcarriers,
- determining one or more channel phase slope values corresponding to one or more pairs of the plurality of pilot subcarriers;
- and
- summing the one or more channel phase slope values;
- and
- determining the timing offset estimate based on the channel phase slope;
- determining a tuning value by passing the timing offset estimate through a proportional-integral controller;
- determining a modified reference signal by modifying a reference oscillator based on the tuning value;
- and
- controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.
A wireless audio microphone system comprising:
- an audio transmitter configured to:
- transmit a plurality of pilot subcarriers;
- and
- one or more audio 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 passing the timing offset estimate through a proportional-integral controller, wherein determining the tuning value comprises applying weighted coefficients to (i) the timing offset estimate and (ii) an integration of previously determined timing offset estimates;
- determine a modified reference signal by modifying a reference oscillator based on the tuning value;
- and
- control (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.
An audio receiver of a wireless audio system, the audio receiver comprising:
- an antenna configured to receive a plurality of pilot subcarriers from an audio transmitter;
- and
- circuitry configured to:
- determine a timing offset estimate based on the plurality of pilot subcarriers;
- determine a tuning value based on the timing offset estimate by applying weighted coefficients to (i) the timing offset estimate and (ii) an integration of previously determined timing offset estimates;
- determine a modified reference signal based on the tuning value;
- and
- control (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.
Dependencies are inferred from the claim text.