RECEIVER DESIGN FOR GEO-LOCATION AND/OR PHASE COHERENT PROCESSING

• US 20140010227A1
• Filed: 07/05/2013
• Published: 01/09/2014
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Angsuman Rudra, Dipak Roy
• Original Assignee: Dipak Roy
• Inventors: ROY, Dipak, RUDRA, Angsuman
• Granted Patent: US 9,232,489 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/002 Mutual synchronization

Abstract

A receiver system using commercially available super high-speed data converters that are able to directly digitize at multiple GHz sampling rates with sufficient accuracy to fit many radio applications. Unlike conventional receivers, no down converters or mixing stages are required. Instead it uses a bank of RF filters from which the desired RF filter, based on the frequency band of interest, is switched in. The frequency spectrum scan rate is very fast as the settling time for the simple RF front-end is small and the speed of RF switching is high. The filtered output is digitized at a multiple GHz sampling rate and all signal processing is done by FPGA or a combination of FPGA and/or a general-purpose processor.

Claims

1. A method for synchronizing a plurality of radio frequency receivers, the method comprising:

a) providing said plurality of radio frequency receivers, each one of said radio frequency receivers being equipped with an ultra high speed clock for clocking a reception of radio signals for said receivers;

b) providing said plurality of radio frequency receivers at a single location;

c) synchronizing clocks of said plurality of radio frequency receivers;

d) placing each of said plurality of radio frequency receivers in hibernation such that each radio frequency receiver'"'"'s clock is operational and continues its clocking;

e) locating each of said plurality of radio frequency receivers at locations physically remote from each other.

2. A method according to claim 1 wherein each of said high speed clocks operates at a very high speed for directly digitizing RF signals.

3. A method according to claim 1 wherein each of said plurality of radio frequency receivers digitizes received wireless signals at a rate of at least 1×

10⁹ samples/sec

4. A system for receiving multiple wireless signals, the system comprising:

at least two radio frequency receivers for receiving said wireless signals and for digitizing wireless signals received, each of said at least two radio frequency receivers comprises an ultra high speed clock for clocking digitization of said wireless signals;

a central processing station controlling said at least two radio frequency receivers, said central processing station being physically remote from each of said at least two radio frequency receivers;

an ultra-high speed data link connecting said at least two radio frequency receivers and said central processing station;

wherein

said at least two radio frequency receivers receive said wireless signals, digitizes said wireless signals, and sends digitized wireless signals to said central processing station by way of said data link;

said ultra-high speed clock at each of said at least two radio frequency receivers are synchronized with clocks for said other radio frequency receivers.

5. A system according to claim 4 wherein said ultra-high speed data link transfers data at a rate of at least 1 Gbits/sec.

6. A system according to claim 5 wherein said ultra-high speed data link transfers data at a rate of at least 10 Gbits/sec

7. A system according to claim 4 wherein each of said radio frequency receivers digitizes received wireless signals at a rate of at least 1×

10⁹ samples/sec.

8. A system according to claim 4 wherein clocks for each of said at least two radio frequency receivers are synchronized according to a method comprising:

a) providing said clocks for said at least two radio frequency receivers at a single location;

b) synchronizing clocks of said at least two radio frequency receivers;

c) placing each of said at least two radio frequency receivers in hibernation such that each radio frequency receiver'"'"'s clock is operational and continues its clocking;

d) locating each of said at least two radio frequency receivers at locations physically remote from each other.

9. A system according to claim 4 wherein said system is used in a geo-location scheme using time difference of arrival (TDOA).

10. A system according to claim 4 wherein each of said at least two radio frequency receivers are devoid of mixing stages.

11. A system according to claim 4 wherein each of said at least two radio frequency receivers are devoid of local oscillators for mixing analog RF signals.

12. A system according to claim 4 wherein at least one of said at least two radio frequency receivers comprises:

a low noise amplifier for amplifying wireless signals received by said radio frequency receiver to result in an amplified signal;

a plurality of RF filters for receiving and filtering said amplified signal, each of said RF filters being for filtering and isolating at least one frequency band of said amplified signal, each of said RF filters producing an isolated signal;

a high speed analog to digital converter (ADC)for digitizing an isolated signal from one of said plurality of RF filters to result in a digitized signal, said ADC being for digitizing said isolated signal at a sampling rate of at least 1×

10⁹ samples per second;

a plurality of switches for coupling said plurality of RF filters with said ADC, said plurality of switches being configured such that a specific RF filter is coupled to said ADC when a specific switch is active;

wherein said digitized signal from said ADC is transmitted to said central processing station by way of said ultra-high speed data link.

13. A receiver system for receiving wireless signals, the receiver comprising:

a low noise amplifier for amplifying wireless signals received by said receiver system to result in an amplified signal;

a plurality of RF filters for receiving and filtering said amplified signal, each of said RF filters being for filtering and isolating at least one frequency band of said amplified signal, each of said RF filters producing an isolated signal;

a high speed analog to digital converter (ADC)for digitizing an isolated signal from one of said plurality of RF filters to result in a digitized signal, said ADC being for digitizing said isolated signal at a sampling rate of at least 1×

10⁹ samples per second;

a plurality of switches for coupling said plurality of RF filters with said ADC, said plurality of switches being configured such that a specific RF filter is coupled to said ADC when a specific switch is active;

wherein said digitized signal from said ADC is transmitted to a processing station by way of an ultra-high speed data link.

14. A system according to claim 13 wherein said ultra-high speed data link transfers data at a rate of at least 1 Gbits/sec.