Carrier frequency offset (cfo) estimator with low complexity and high accuracy for orthogonal-frequency-division-multiplexing (co-ofdm) systems
AssigneeNEC Laboratories America, Inc.
InventorsMingzheng Cao, Dayou Qian
Life of this patent
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Abstract
A system and method are provided for carrier frequency offset (CFO) estimation for coherent optical orthogonal-frequency-division-multiplexing (CO-OFDM) broadband systems. The method includes obtaining an initial estimate of a normalized CFO with an estimation range equal to ±L/2 subcarrier subspacing using a single training symbol with L identical portions. The method further includes obtaining a maximum likelihood (ML) estimate of the CFO by performing a local grid search based on the initial estimate.
Claims18
A method for carrier frequency offset (CFO) estimation for coherent optical orthogonal-frequency-division-multiplexing (CO-OFDM) broadband systems, comprising:
- obtaining an initial estimate of a normalized CFO with an estimation range equal to +L/2 subcarrier subspacing using a single training symbol with L identical portions;
- storing the initial estimate in a memory device;
- and
- obtaining a maximum likelihood (ML) estimate of the CFO by performing a local grid search based on the initial estimate.
A system for carrier-frequency-offset (CFO) estimation for coherent optical orthogonal-frequency-division-multiplexing (CO-OFDM) broadband systems, comprising:
- an initial carrier frequency offset estimator for obtaining an initial estimate of a normalized CFO with an estimation range equal to ±L/2 subcarrier subspacing using a single training symbol with L identical portions;
- a memory for storing the initial estimate;
- and
- a maximum likelihood estimator for obtaining a maximum likelihood (ML) estimate of the CFO by performing a local grid search based on the initial estimate.
Dependencies are inferred from the claim text.