Interference cancellation system and method

• US 7,822,126 B2
• Filed: 08/10/2006
• Issued: 10/26/2010
• Est. Priority Date: 08/10/2006
• Status: Active Grant

• Current Assignee: Edgewater Computer Systems Inc.
• Original Assignee: Edgewater Computer Systems Inc.
• Inventors: Fanson, John
• Primary Examiner(s): Tran; Khanh C
• Application Number:
  US11/463,860
• Publication Number:
  US 20100111237A1
• Time in Patent Office: 1,538 Days
• Field of Search: 375/257, 375/346, 375/348, 375/350, 370/503
• US Class Current: 375/257
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H

Abstract

An interference cancellation system and method for a communication system comprising a data bus carrying primary signals having an A component and a non-A component are provided. The interference cancellation system has an input port, an A data extraction block and an interference cancellation circuit. The input port receives a sampled primary signal from the data bus, via an analog-front end block having sampling means. The A data extraction block extracts A data from the sampled primary signal and outputs A decoded data. The interference cancellation circuit has an interference measurement block and a cancellation block. The interference measurement block receives the A decoded data and the sampled primary signal and produces an A interference signal. The cancellation block receives the sampled primary signal and the A interference signal and subtracts the A interference signal from the sampled primary signal, producing an output signal with the A component substantially attenuated.

Claims

1. Within a 1553 communication system comprising a data bus carrying primary signals having a 1553 component and a non-1553 component, an interference cancellation system comprising:

an input port for receiving a sampled primary signal from the data bus, via an analog-front end block comprising sampling means;

a 1553 data extraction block connected to said input port, for extracting 1553 data from said sampled primary signal and for outputting 1553 decoded data, wherein the 1553 decoded data further comprises a 1553 word timing estimate; and

an interference cancellation circuit comprising;

an interference measurement block for receiving said 1553 decoded data and said sampled primary signal and for producing an interference signal the interference measurement block comprising an accumulate basis function block, for receiving said 1553 decoded bit stream, said 1553 word timing and said sampled primary signal and for extracting 1553 basis function representations in a non-1553 frequency band; and

a cancellation block for subtracting the interference signal from the sampled primary signal and for producing an output signal.

2. The interference cancellation system of claim 1, wherein the interference measurement block further comprises a 1553 synthesis block for synthesizing a 1553 interference signal based on said accumulated basis functions and said 1553 decoded bit stream.

3. Within a 1553 communication system comprising a data bus carrying primary signals having a 1553 component and a non-1553 component, an interference cancellation system comprising:

an input port for receiving a sampled primary signal from the data bus, via an analog-front end block comprising sampling means;

a 1553 data extraction block connected to said input port, for extracting 1553 data from said sampled primary signal and for outputting 1553 decoded data, wherein the 1553 decoded data further comprises a 1553, word timing estimate; and

an interference cancellation circuit comprising;

an interference measurement block for receiving said 1553 decoded data and said sampled primary signal and for producing an interference signal said interference measurement block comprising an accumulate basis functions block for extracting samples of the 1553 component from said sampled primary signal, based on identifying predefined basis functions within the 1553 decoded bit stream; and

a cancellation block for subtracting the interference signal from the sampled primary signal and for producing an output signal.

4. The interference cancellation system of claim 3, wherein said accumulate basis functions block has a plurality of averaging buffers associated with said predefined 1553 basis functions, for accumulating said extracted samples.

5. The interference cancellation system of claim 4, wherein within each said averaging buffer said accumulated extracted samples are integrated over a predetermined period of time.

6. The interference cancellation system of claim 3, wherein said predefined 1553 basis functions correspond to predefined sequences of three 1553 symbols.

7. The interference cancellation system of claim 3, wherein the interference measurement block further comprises a first resampler block for time aligning said samples of the 1553 component extracted from said sampled primary signal prior to extraction within the accumulate basis function block.

8. The interference cancellation system of claim 7, wherein said first resampler further uses a clock error estimate in the time alignment operation.

9. The interference cancellation system of claim 7, wherein said first resampler further uses a 1553 word timing estimate in the time alignment operation.

10. Within a 1553 communication system comprising a data bus carrying primary signals having a 1553 component and a non-1553 component, an interference cancellation system comprising:

an input port for receiving a sampled primary signal from the data bus, via an analog-front end block comprising sampling means;

a 1553 data extraction block connected to said input port, for extracting 1553 data from said sampled primary signal and for outputting 1553 decoded data, wherein the 1553 decoded data further comprises a 1553 word timing estimate; and

an interference cancellation circuit comprising;

an interference measurement block for receiving said 1553 decoded data and said sampled primary signal and for producing an interference signal, said interference measurement block comprising an accumulate basis functions block for extracting samples of the 1553 component from said sampled primary signal, based on identifying predefined basis functions within the 1553 decoded bit stream; and

a cancellation block for subtracting the interference signal from the sampled primary signal and for producing an output signal; and

means for storing interference cancellation parameters IC_1553TXi associated with primary signals incorporating 1553 components transmitted by 1553 transmitter 1553Txi within the 1553 communication system.

11. Within a 1553 communication system comprising a data bus carrying primary signals having a 1553 component and a non-1553 component, an interference cancellation system comprising:

an input port for receiving a sampled primary signal from the data bus, via an analog-front end block comprising sampling means;

a 1553 data extraction block connected to said input port, for extracting 1553 data from said sampled primary signal and for outputting 1553 decoded data, wherein the 1553 decoded data further comprises a 1553 word timing estimate; and

an interference cancellation circuit comprising;

an interference measurement block for receiving said 1553 decoded data and said sampled primary signal and for producing an interference signal; and

a cancellation block for subtracting the interference signal from the sampled primary signal and for producing an output signal,

said interference cancellation system being electrically connected to both a primary data bus and a redundant data bus, for enabling interference cancellation for non-1553 dual redundant data communication.