Apparatus and method for estimating a doppler frequency and a moving velocity of a wireless terminal
First Claim
1. A Doppler frequency estimator, comprising:
- a filter bank configured to receive demodulated signals and filter the demodulated signals of a plurality of frequency bands to provide a plurality of filtered signals;
a non-coherent accumulator configured to execute a non-coherent accumulation on each of the filtered signals to provide a plurality of accumulated signals; and
a maximum value detector configured to detect a signal having a largest value of the accumulated signals to provide a center frequency of a frequency band corresponding to the detected signal.
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Abstract
An apparatus and method for estimating a Doppler frequency and a moving velocity of a wireless terminal are disclosed. The Doppler frequency estimator includes a filter bank, a non-coherent accumulator, and a maximum value detector. The filter bank filters demodulated signals with respect to frequency bands to provide a plurality of filtered signals. The non-coherent accumulator executes a non-coherent accumulation on each of the filtered signals to provide accumulated signals. The maximum value detector detects a signal having a largest value of the accumulated signals to provide a center frequency of a band corresponding to the detected signal as a Doppler frequency.
26 Citations
21 Claims
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1. A Doppler frequency estimator, comprising:
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a filter bank configured to receive demodulated signals and filter the demodulated signals of a plurality of frequency bands to provide a plurality of filtered signals;
a non-coherent accumulator configured to execute a non-coherent accumulation on each of the filtered signals to provide a plurality of accumulated signals; and
a maximum value detector configured to detect a signal having a largest value of the accumulated signals to provide a center frequency of a frequency band corresponding to the detected signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of estimating a Doppler frequency, comprising:
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filtering demodulated signals of a plurality of frequency bands to provide a plurality of filtered signals;
executing a non-coherent accumulation on each of the filtered signals to provide a plurality of accumulated signals; and
detecting a signal having a largest value of the accumulated signals to provide a center frequency of a frequency band corresponding to the detected signal. - View Dependent Claims (9, 10, 11)
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12. A Doppler frequency estimator, comprising:
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a band-pass filter unit configured to perform a band-pass filtering operation on demodulated signals of a modulo-2 search band to provide filtered signal pairs;
a non-coherent accumulator configured to execute a non-coherent accumulation on each of the filtered signal pairs to provide non-coherent accumulated signal pairs;
a comparator configured to compare the non-coherent accumulated signal pairs with each other to provide a larger one of the non-coherent accumulated signal pairs as a detection signal; and
a search control unit configured to generate control signals by narrowing a search band for a number of search periods to provide the control signals to the band-pass filter unit, and configured to determine that a detection signal detected at a final search period is a Doppler frequency, wherein the control signals set an initial modulo-2 search band when a searching operation is initiated and set a divided band corresponding to the detection signal among the initial modulo-2 search band as a modulo-2 search band of a next period. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A method of calculating a Doppler frequency, comprising:
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performing a band-pass filtering operation on demodulated signals of a modulo-2 search band to provide filtered signal pairs;
executing a non-coherent accumulation on each of the filtered signal pairs to provide non-coherent accumulated signal pairs;
comparing the non-coherent accumulated signal pairs with each other to provide a larger one of the non-coherent accumulated signal pairs as a detection signal;
generating control signals by narrowing a search band for a number of search periods to provide the control signals to the band-pass filter unit; and
determining that a detection signal detected at a final search period is a Doppler frequency, wherein the control signals set an initial modulo-2 search band when a searching operation is initiated, and set a divided band corresponding to the detection signal among the initial modulo-2 search band as a modulo-2 search band of a next period. - View Dependent Claims (20, 21)
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Specification