Correlation computation method, device and system

1. A signal processing method for correlation computation between received signal samples, a code replica, and a carrier replica, comprising:

mapping received signal samples from a numeric range of the received signal samples into a range of unsigned integers having a same number of bits as the received signal samples;

separating bits of mapped N-bit sample sequences into at least N sequences of bits that are ordered from a most significant bit to a least significant bit, and giving a multiplier to each sequence of bits based on bit position in the mapped sample sequence;

performing at least one exclusive-or (XOR) operation between a sequence of bits and the code replica over a predetermined number of samples;

counting a number of bits having a value 1 in a result of the X©R operation, multiplying the number of bits having a value 1 with the given multiplier of the sequence of bits, and summing products resulting from each sequence of bits for which the XOR operation is performed;

remapping a sum of the products back into the numeric range of the received signal samples;

multiplying the remapped sum by the carrier replica; and

accumulating a product of the multiplying the remapped sum by the carrier replica for an interval of at least a code epoch.

2. The method of claim 1 , wherein received signal samples are complex values comprising in-phase (I) sample values and quadrature-phase (Q) sample values that are both separated individually in the separating, and the carrier replica is in complex values.

3. The method of claim 1 , wherein after the mapping, even and odd numbered samples of mapped received signal samples are separated into individual sample sequences that are processed by the method separately until the accumulating; and even and odd numbered samples of the code replica are separated into individual sample sequences that are processed by the method separately until the accumulating.

4. The method of claim 1 , wherein performing at least XOR operation between a sequence of bits and the code replica over a predetermined number of samples includes selecting the sequence of bits based on signal strength of previous correlation computations.

5. The method of claim 1 , wherein separating bits of mapped N-bit sample sequences into at least N sequences of bits includes reordering bits separated from sample sequences into different orders to minimize a number of operations needed for separating, and reordering bits separated from the code replica into a different order to minimize a number of operations needed for separating.

6. The method of claim 1 , wherein in performing at least one XOR operation between a sequence of bits and the code replica, the predetermined number of samples is determined based on a frequency of the carrier.

7. A signal processing module for correlation computation between received signal samples, a code replica, and a carrier replica, comprising:

a sample mapper configured for mapping received signal samples from a numeric range of the received signal samples into a range of unsigned integers having a same number of bits as the received signal samples;

a bit separator configured for separating bits of mapped N-bit sample sequences into N sequences of bits that are ordered from a most significant bit to a least significant bit and giving a multiplier to each sequence of bits based on bit position in the mapped sample sequence;

an exclusive-or (XOR) device configured for performing at least one XOR operation between a sequence of bits and the code replica over a predetermined number of samples;

a counter configured for counting a number of bits having a value 1 in a result of the XOR operation, a first multiplier configured for multiplying the number of bits having a value 1 with the given multiplier of the sequence of bits, and a summer configured for summing products of the first multiplier that result from each sequence of bits for which the XOR operation is performed;

a remapper configured for remapping a sum of the summer back into the numeric range of the received signal samples;

a second multiplier configured for multiplying a remapped sum by the carrier replica; and

an accumulator configured for accumulating a product of the second multiplier for an interval of at least a code epoch.

8. A device, comprising a signal processing module for correlation computation between received signal samples, a code replica, and a carrier replica, comprising:

a sample mapper configured for mapping received signal samples from a numeric range of the received signal samples into a range of unsigned integers having a same number of bits as the received signal samples;

a bit separator configured for separating bits of mapped N-bit sample sequences into N sequences of bits that are ordered from a most significant bit to a least significant bit and giving a multiplier to each sequence of bits based on bit position in the mapped sample sequence;

an exclusive-or (XOR) device configured for performing at least one XOR operation between a sequence of bits and the code replica over a predetermined number of samples;

a counter configured for counting a number of bits having a value 1 in a result of the XOR operation, a first multiplier configured for multiplying the number of bits having a value 1 with the given multiplier of the sequence of bits, and a summer configured for summing products of the first multiplier that result from each sequence of bits for which the XOR operation is performed;

a remapper configured for remapping a sum of the summer back into the numeric range of the received signal samples;

a second multiplier configured for multiplying a remapped sum by the carrier replica; and

an accumulator configured for accumulating a product of the second multiplier for an interval of at least a code epoch.

9. The device of claim 8 , wherein the device is included in a positioning system.

10. The device of claim 8 , wherein the device is included in a navigation system.