Using preamble portion having irregular carrier spacing for frequency synchronization
AssigneeSilicon Laboratories Inc.
InventorFrederic Pirot
Life of this patent
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Abstract
In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.
Claims20
An apparatus comprising:
- a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission;
- a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal;
- and
- a baseband circuit coupled to the digitizer to process the digital signal, wherein the baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.
A method comprising:
- receiving an orthogonal frequency division multiplexing (OFDM) transmission in a receiver;
- and
- performing a frequency estimation on a first preamble portion of the OFDM transmission using a plurality of correlators of the receiver, the first preamble portion formed of a plurality of symbols, each of the plurality of symbols having N−M non-zero carriers, wherein at least some of the N−M non-zero carriers are irregularly spaced, wherein N is a number of carriers in a symbol and M is a number of the carriers in the symbol having a zero value, N greater than M.
A system comprising:
- an antenna to receive and transmit radio frequency (RF) signals;
- and
- an integrated circuit coupled to the antenna, the integrated circuit comprising:
- a transmitter to generate and transmit an orthogonal frequency division multiplexing (OFDM) transmission, the transmitter comprising a preamble generation circuit to generate a first portion of a preamble of the OFDM transmission having a first plurality of symbols, each of the first plurality of symbols having a plurality of carriers, wherein a first subset of the plurality of carriers have non-zero values, at least some of the first subset of the plurality of carriers having irregular carrier spacing.
Dependencies are inferred from the claim text.