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US 8,478,325 B2Granted
Low sample rate peak power reduction
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsNeil McGowan, Marthinus Willem Da Silveira, Peter Zahariev Rashev
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Abstract
Peak power reduction in transmit chains of radiocommunication devices is performed using a low sample rate. Filtering and, optionally, interpolation of a signal being processed for peak power reduction can be performed only in an error signal path or in both an error signal path and a primary signal path.
Claims14
A method for reducing peak power of a signal, comprising:
- providing a first input signal to a first peak power reduction stage on both a first primary signal path and on a first error signal path;
- time shifting said first input signal on said first error signal path by a first predetermined time increment to generate a first time shifted input signal;
- generating a first error signal based on a peak power threshold using said first time shifted input signal;
- filtering said first error signal to remove out-of-band signal energy and to reverse time shift said first error signal by said first predetermined time increment to generate a first filtered error signal;
- and
- subtracting said first filtered error signal in said first error signal path from said first input signal in said first primary signal path to generate a first clipped output signal.
3 more elements
A transmitter comprising:
- a processor configured to generate signals for transmission;
- and
- a plurality of transmit chain elements configured to process said signals including:
- a first stage of a peak power reduction circuit having a first input signal which is provided to a first primary signal path and to a first error signal path, said first stage of said peak power reduction circuit further comprising:
- a first time shifting element configured to time shift said first input signal on said first error signal path by a first predetermined time increment to generate a first time shifted input signal;
- a first error signal generating element configured to generate a first error signal based on a peak power threshold using said first time shifted input signal;
- a first filter configured to filter said first error signal to remove out-of-band signal energy and to reverse time shift said first error signal by said first predetermined time increment to generate a first filtered error signal;
- and
- a first summer configured to subtract said first filtered error signal in said first error signal path from said first input signal in said first primary signal path to generate a first clipped output signal.
6 more elements
Dependencies are inferred from the claim text.