Claims
- 1. An engine for detecting a code sequence in input data, the code sequence being a sum of a first code sequence and a second code sequence, the detection engine comprising:
a data input line for receiving input data; a code input line for selectively receiving the first code sequence or the second code sequence, the first code sequence having a period longer than a period for the second code sequence; a despreader coupled to the data input line, and the code input line, the despreader producing a despread result between the first code sequence and the input data; and a plurality of memory registers coupled to the despreader, wherein each of the plurality of memory registers stores only a portion of the despread results.
- 2. The detection engine recited in claim 1 wherein each of the plurality of memory registers only stores a despread results for a given periodic offset from the first despread result, the given periodic offset equal to the period of the second code sequence.
- 3. The detection engine recited in claim 1 wherein the plurality of memory registers is at least equal to the period of the second code sequence.
- 4. The detection engine recited in claim 1 wherein an nth memory register stores a correlation result between one bit of the input data and one bit of the first code sequence at an nth offset of the second code sequence.
- 5. The detection engine recited in claim 1 wherein each of the memory registers stores accumulated despread results for over a search window period.
- 6. The detection engine recited in claim 1 wherein each of the memory registers stores correlation results for a fraction of a search window period.
- 7. The detection engine recited in claim 1 wherein the plurality of memory registers at least twice the period of the second code sequence for a ping-pong memory operation.
- 8. The detection engine recited in claim 1 further comprising:
an additional correlator for correlating the second code sequence with the correlation results from the first code sequence and the input data.
- 9. The detection engine recited in claim 1 further comprising;
a selective interconnect for providing the second code sequence to a secondary descrambling operation between using descrambled results from the first code sequence.
- 10. A detection system for detecting a composite code sequence in input data, the composite code sequence being a sum of a first code sequence and a second code sequence, the detection engine comprising:
a memory for storing input data; a bus coupled to the memory; and a plurality of processing engines coupled to the bus in parallel, the plurality of processing engines for storing despread results between only the first code sequence and the input data.
- 11. The detection system recited in claim 10 wherein each of the plurality of detection engines has a plurality of memory registers, each of the plurality of memory registers storing only a portion of the correlation result between the input data and the second code sequence.
- 12. The detection system recited in claim 10 further comprising:
a code input line coupled to each of the plurality of correlation engines; and a plurality of delay operators coupled to the code input line.
- 13. The detection system recited in claim 10 wherein one of the plurality of delay operator is coupled to one of the plurality of processing engines except a first processing engine.
- 14. The detection system recited in claim 12 wherein the delay for each of the plurality of delay operators is a value of one for performing parallel searches with different offsets.
- 15. The detection system recited in claim 12 wherein the plurality of delay operators is a value equal to the code space divided by the number of processing engines performing a piecewise search of a single offset between the input data and the first code sequence.
- 16. The detection system recited in claim 12 wherein the memory is partitioned to allow each of the plurality of processing engines access to offset portions of input data.
- 17. A method of detecting a composite code sequence in input data using a processing engine, the method comprising the steps of:
a) receiving input data with the composite code sequence, the composite code sequence being a combination of a first code sequence and a second code sequence; b) receiving the first code sequence, the first code sequence having a possible offset with respect to the input data; c) descrambling the input data with the first code sequence to obtain descrambled results; and d) storing only a portion of the descrambled results in one of a plurality of memory locations.
- 18. The method recited in claim 17 further comprising the steps of:
e) accumulating each of the portions of descrambled results that occurred at a periodic location, the periodic location equal to the length of the second code sequence.
- 19. The method recited in claim 17 further comprising the steps of:
e) descrambling a sample of the first code sequence with the sample of the input data to obtain a descrambled result; and d) storing the descrambled result in a portion of memory.
- 20. The method recited in claim 17 further comprising the step of:
e) repeating receiving step a) through storing step d) for a subsequent sample of the first code sequence, a subsequent sample of the input data, and a subsequent portion of memory, for a period equal to the length of the second code sequence; f) adding the results from memory for descrambling steps performed at the same periodic position to obtain a partial sum of correlation results, the period equal to the length of second code sequence; and g) overwriting the partial sum of correlation results in the memory.
- 21. The method recited in claim 17 further comprising the step of:
g) repeating steps e) through f) until the length of a desired search window is attained; h) reading the partial sum of descrambled results from the memory; i) receiving a sample of the second code sequence; j) descrambling the sample of the second code sequence with the partial sum of descrambled results from the memory; e) repeating receiving step a) through storing step d) for a subsequent sample of the first code sequence, a subsequent sample of the input data, and a subsequent portion of memory, for a period equal to the length of the second code sequence; f) adding the results from memory for descrambled steps performed at the same periodic position in the descrambling process to obtain a partial sum of correlation results; and g) overwriting the partial sum of descrambled results in the memory.
- 22. An engine for detecting a code sequence in input data, the code sequence being a sum of a first code sequence and a second code sequence, the engine comprising:
a data input line for receiving input data; a code input line for selectively receiving the first code sequence or the second code sequence, the first code sequence having a period longer than a period for the second code sequence; a means for despreading the data input line, and the code input line, the means for despreading producing a despread result between the first code sequence and the input data; and a plurality of memory registers coupled to the despreader, wherein each of the plurality of memory registers stores only a portion of the despread results.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to the provisional patent application with the following Ser. No. 60/222,855, filed on Aug. 3, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60222855 |
Aug 2000 |
US |