Transmit signal squelch at symbol boundaries
AssigneeAnalog Devices International Unlimited Company
InventorMark Cope
Life of this patent
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Abstract
Aspects of this disclosure relate to squelching a symbol at a symbol boundary. A transmit squelch block can squelch a portion of a symbol at a symbol boundary. The transmit squelch block can be included in a symbol based envelope tracking system. Transmit squelching can reduce spurious emissions associated a symbol based envelope tracking voltage toggling on a symbol boundary.
Claims20
A system with transmit squelching at symbol boundaries, the system comprising:
- a transmit squelch block configured to squelch a portion of a symbol corresponding to a symbol boundary to generate a transmit squelch symbol;
- a voltage modulator configured to generate an output bias voltage that tracks a root mean square symbol power of a radio frequency signal, the voltage modulator configured to adjust the output bias voltage on symbol boundaries, and the radio frequency signal comprising a representation of the transmit squelch symbol;
- and
- a power amplifier configured to receive the output bias voltage and to amplify the radio frequency signal.
A transceiver with transmit squelching at symbol boundaries, the transceiver comprising:
- a transmit squelch block configured to squelch a portion of symbol corresponding to a symbol boundary to generate a transmit squelch symbol, wherein the symbol comprises a cyclic prefix, wherein the portion of the symbol is part of the cyclic prefix, and wherein the transmit squelch symbol comprises a cyclic prefix that is shorter than the cyclic prefix of the symbol;
- and
- a digital upconverter configured to upconvert the transmit squelch symbol in a digital domain.
A method of radio frequency signal amplification with symbol based envelope tracking with transmit squelch, the method comprising:
- toggling an output bias voltage between a plurality of discrete voltage levels on symbol boundaries of a radio frequency signal based on a symbol based envelope tracking state, wherein the output bias voltage is provided to a power amplifier;
- squelching a portion of a symbol to generate a transmit squelch symbol, wherein the portion of the symbol abuts a boundary of the symbol;
- and
- after the squelching, amplifying the radio frequency signal with the power amplifier, wherein the radio frequency signal comprises a representation of the transmit squelch symbol.
Dependencies are inferred from the claim text.