Dynamic trigger compensation in OFDM systems
Systems and methods for enabling pre-compensation of timing offsets in OFDM receivers without invalidating channel estimates are described. Timing offset estimations may be sent along with the received OFDM symbols for FFT computation and generating a de-rotated signal output. The timing offset estimation may provide a reference point for dynamic tracking of timing for an OFDM signal and estimated based on an integral value associated with the OFDM signal.
1. A non-transitory computer readable medium containing instructions that, when executed by at least on processor of a computing device, cause the computing device to provide multi-carrier receiving, comprising:
receiving, by a multi-carrier receiver system, a frequency modulated signal;
determining, by the multi-carrier receiver system, a timing reference point associated with the frequency modulated signal;
determining, by the multi-carrier receiver system, a timing offset based on the timing reference point; and
generating, by the multi-carrier receiver system, a demodulated signal based on applying a compliment of the timing offset to a set of samples of the frequency modulated signal after conversion into the frequency domain.
2. The non-transitory computer readable medium of claim 1 , wherein the set of samples of the frequency modulated signal are selected based on a dynamic timing parameter.
3. The non-transitory computer readable medium of claim 2 , wherein the timing offset is further based on the dynamic timing parameter.
4. The non-transitory computer readable medium of claim 3 , wherein the timing offset is calculated based on a difference between a value of the dynamic timing parameter and a value of the timing reference point.
5. The non-transitory computer readable medium of claim 1 , wherein the determining the timing reference point is based on correlating the frequency modulated signal with a delayed copy of the frequency modulated signal.
6. The non-transitory computer readable medium of claim 1 , wherein the set of samples are converted into the frequency domain by performing a Fast Fourier Transform, and wherein the timing reference point corresponds to an orthogonal frequency division multiplexing (OFDM) symbol.
7. The non-transitory computer readable medium of claim 1 , further comprising:
updating a value of the timing offset for each symbol of the frequency modulated signal.
8. The non-transitory computer readable medium of claim 1 , wherein the generating the demodulated signal further comprises correction of the phase of the set of samples after performing a Fast Fourier Transform and based on CORDIC functions.
9. The non-transitory computer readable medium of claim 8 , wherein the correction of the phase comprises application of a linear phase correction to the set of samples that de-rotates the samples back to the timing reference point.
10. The non-transitory computer readable medium of claim 1 , further comprising:
performing channel equalization based on applying a channel estimate to the demodulated signal.