Receiver comprising a device for correcting doppler effect
AssigneeSTMicroelectronics International N.V.
InventorChristophe Del-Toso
Life of this patent
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Abstract
A OFDM digital communication receiver having channel estimate and correction means and inter carrier interference cancellation means based on the use of a temporal digital filter comprising a set of digital coefficients. The receiver includes n Look-Up Tables LUT(n), each corresponding to a given set of digital coefficients and an entry pointer.
Claims33
An Orthogonal Frequency Division Multiplexing (OFDM) digital communication receiver to receive signals transmitted on N carriers assigned to respective frequency bands, where N is a positive integer, the receiver comprising:
- a memory for storing n Look-Up Tables LUT(n) where n is a positive integer, each table corresponding to a given set of determined digital coefficients, wherein the sets of coefficients are a function of:
- a mathematical model of Doppler spectrum;
- a Doppler frequency;
- and
- a signal to noise ratio, wherein each table comprises an entry pointer;
- a channel estimation block configured to receive periodic position (P), velocity (V) and temporal (T) (PVT) information related to the receiver with respect to a terrestrial reference frame;
- wherein the PVT information is used by the channel estimation block to derive an instantaneous velocity of the receiver and a Doppler frequency associated with a selected carrier of the N carriers;
- the channel estimation block is further configured to point to one of the entry pointers of the LUT(n) and select a set of coefficients based on the Doppler frequency associated with the selected carrier;
- and
- a filter block configured to filter a digital signal from the selected carrier based on the selected set of coefficients.
A method of controlling communications in a communications system having a receiver with at least one processor, the method comprising:
- storing in the receiver a set of look-up tables of sets of digital coefficients, wherein the stored sets of digital coefficients are a function of a mathematical model of Doppler spectrum, a Doppler frequency and a signal to noise ratio;
- calculating, under the control of the at least one processor, an instantaneous velocity of the receiver from periodic position P, velocity V and temporal T information about the receiver provided from a Global Positioning System (GPS) block;
- calculating, under the control of the at least one processor, a Doppler frequency associated with a considered carrier and for the instantaneous velocity;
- selecting, under control of the at least one processor, a set of coefficients from a table in the set of tables based on the calculated Doppler frequency;
- and
- filtering a digital signal based on the selected set of coefficients from the considered carrier frequency.
A communication device comprising:
- a global positioning block configured to generate position P, velocity V and temporal T information;
- a control block configured to calculate an instantaneous velocity and a Doppler frequency associated with a considered carrier frequency from the P, V and T information;
- a Doppler compensation controller configured to select a set of coefficients from stored sets of coefficients based on the Doppler frequency;
- and
- a channel estimation and control block configured to compensate for a Doppler effect on the considered carrier frequency based on the selected set of coefficients.
A non-transitory computer-readable media whose contents cause at least one processor in a communications system to perform a method of controlling communications, the method comprising:
- storing, in a receiver of the communication system, sets of digital coefficients, wherein the stored sets of digital coefficients are a function of a mathematical model of Doppler spectrum, a Doppler frequency and a signal to noise ratio;
- selecting, under control of the at least one processor, a set of coefficients from the stored sets of coefficients based on a calculated Doppler frequency for a considered carrier frequency based on an instantaneous velocity derived from periodic position P, velocity V, and temporal information related to the receiver;
- and
- compensating, under control of the at least one processor, for a Doppler effect based on the selected set of coefficients.
Dependencies are inferred from the claim text.