Wideband frequency discriminator and radiolocalization receiver
First Claim
1. A method comprising, with an apparatus having a receiver for receiving a radio frequency (RF) signal:
- obtaining a number of N successive samples associated with the RF signal;
applying a discrete number of operators to the number of N successive samples to extract spectral components associated with the received RF signal;
determining a lower frequency value for the extracted spectral components using a lower compound operator having a first transfer function with its maximum at a lower frequency that is below a reference frequency and which exhibits no zeros or discontinuities over an operating frequency range;
determining an upper frequency value for the extracted spectral components using an upper compound operator having a second transfer function with its maximum at an upper frequency that is higher than the reference frequency and which exhibits no zeros or discontinuities in the operating frequency range;
determining a frequency difference based, at least in part, on the lower frequency value and the upper frequency value; and
providing the frequency difference to at least one module of the apparatus.
2 Assignments
0 Petitions
Accused Products
Abstract
A Frequency discriminator based on a combination of Discrete Fourier Transform (DFT) operator and half-bin DFT operator, corresponding to a set of Twiddle factors with frequency double than the sampling frequency. The frequency estimators are so chosen as not to have any zero or discontinuity point. Therefore the discriminator of embodiments of invention is more stable and well-behaved in an extended operating range. The discriminator of the invention, when applied to a Global Positioning System (GPS) receiver, allows a safer lock to the carrier frequency, even in presence of a large initial error, and avoids the problem of false locks.
16 Citations
44 Claims
-
1. A method comprising, with an apparatus having a receiver for receiving a radio frequency (RF) signal:
-
obtaining a number of N successive samples associated with the RF signal; applying a discrete number of operators to the number of N successive samples to extract spectral components associated with the received RF signal; determining a lower frequency value for the extracted spectral components using a lower compound operator having a first transfer function with its maximum at a lower frequency that is below a reference frequency and which exhibits no zeros or discontinuities over an operating frequency range; determining an upper frequency value for the extracted spectral components using an upper compound operator having a second transfer function with its maximum at an upper frequency that is higher than the reference frequency and which exhibits no zeros or discontinuities in the operating frequency range; determining a frequency difference based, at least in part, on the lower frequency value and the upper frequency value; and providing the frequency difference to at least one module of the apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An apparatus for use with a device having a receiver for receiving a radio frequency (RF) signal, the apparatus comprising:
-
means for obtaining a number of N successive samples associated with a received RF signal; means for extracting spectral components associated with the number of N successive samples using a discrete number of operators; means for determining a lower frequency value for the extracted spectral components using a lower compound operator having a first transfer function with its maximum at a lower frequency that is below a reference frequency and which exhibits no zeros or discontinuities over an operating frequency range; means for determining an upper frequency value for the extracted spectral components using an upper compound operator having a second transfer function with its maximum at an upper frequency that is higher than the reference frequency and which exhibits no zeros or discontinuities in the operating frequency range; means for determining a frequency difference based, at least in part, on the lower frequency value and the upper frequency value; and means for providing the frequency difference to at least one module of the device. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. An apparatus comprising:
-
a receiver for receiving a radio frequency (RF) signal; and a frequency discriminator to; obtain a number of N successive samples associated with the RF signal; apply a discrete number of operators to the number of N successive samples to extract spectral components associated with the received RF signal; determine a lower frequency value for the extracted spectral components using a lower compound operator having a first transfer function with its maximum at a lower frequency that is below a reference frequency and which exhibits no zeros or discontinuities over an operating frequency range; determine an upper frequency value for the extracted spectral components using an upper compound operator having a second transfer function with its maximum at an upper frequency that is higher than the reference frequency and which exhibits no zeros or discontinuities in the operating frequency range; and determine a frequency difference based, at least in part, on the lower frequency value and the upper frequency value. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. An article comprising:
a computer readable storage medium having stored therein computer-implementable instructions executable by a device to; obtain a number of N successive samples associated with a received radio frequency (RF) signal; apply a discrete number of operators to the number of N successive samples to extract spectral components associated with the received RF signal; determine a lower frequency value for the extracted spectral components using a lower compound operator having a first transfer function with its maximum at a lower frequency that is below a reference frequency and which exhibits no zeros or discontinuities over an operating frequency range; determine an upper frequency value for the extracted spectral components using an upper compound operator having a second transfer function with its maximum at an upper frequency that is higher than the reference frequency and which exhibits no zeros or discontinuities in the operating frequency range; determine a frequency difference based, at least in part, on the lower frequency value and the upper frequency value; and provide the frequency difference to at least one module of the device. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
Specification