Method and apparatus for multipath mitigation

A method for multipath mitigation comprising

• obtaining a shape of a local maximum of a correlation function;
• computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if a weaker path is detected;
• subtracting a first stronger path from the correlation function to obtain a first residual signal, wherein one component of the first residual signal is the weaker path;
• locating a valid peak of the first residual signal;
• applying reconstruction on the valid peak of the first residual signal to obtain a first reconstructed weaker path;
• subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• applying reconstruction on the second residual signal to obtain a second stronger path.

An apparatus comprising a processor and a memory, the memory containing program code executable by the processor for performing the following:

• subtracting a first stronger path from a correlation function to obtain a first residual signal, wherein one component of the first residual signal is a weaker path;
• applying reconstruction on the first residual signal to obtain a first reconstructed weaker path;
• subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• applying reconstruction on the second residual signal to obtain a second stronger path.

An apparatus comprising a processor and a memory, the memory containing program code executable by the processor for performing the following:

• obtaining a shape of a local maximum of a correlation function;
• computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if a weaker path is detected;
• subtracting a first stronger path from the correlation function to obtain a first residual signal, wherein one component of the first residual signal is the weaker path;
• locating a valid peak of the first residual signal;
• applying reconstruction on the valid peak of the first residual signal to obtain a first reconstructed weaker path;
• subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• applying reconstruction on the second residual signal to obtain a second stronger path.

A receiver comprising:

• an antenna for receiving a composite receive RF signal from a plurality of sources;
• a receiver front-end for converting the composite receive RF signal into a composite receive digital signal;
• and
• a processor for performing signal correlation on the composite receive digital signal to obtain a correlation function, wherein the processor is coupled to a memory containing program code executable by the processor for performing the following:
• subtracting a first stronger path from a correlation function to obtain a first residual signal, wherein one component of the first residual signal is a weaker path;
• applying reconstruction on the first residual signal to obtain a first reconstructed weaker path;
• subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• applying reconstruction on the second residual signal to obtain a second stronger path.

A computer-readable medium including program code stored thereon, comprising:

• program code for obtaining a shape of a local maximum of a correlation function;
• program code for subtracting a first stronger path from the correlation function to obtain a first residual signal, wherein one component of the first residual signal is a weaker path;
• program code for applying reconstruction on the first residual signal to obtain a first reconstructed weaker path;
• program code for subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• program code for applying reconstruction on the second residual signal to obtain a second stronger path.

A computer-readable medium including program code stored thereon, comprising:

• program code for obtaining a shape of a local maximum of a correlation function;
• program code for computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• program code for comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if a weaker path is detected;
• program code for subtracting a first stronger path from the correlation function to obtain a first residual signal, wherein one component of the first residual signal is the weaker path;
• program code for locating a valid peak of the first residual signal;
• program code for applying reconstruction on the valid peak of the first residual signal to obtain a first reconstructed weaker path;
• program code for subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal;
• and
• program code for applying reconstruction on the second residual signal to obtain a second stronger path.

A method for multipath identification comprising:

• obtaining a shape of a local maximum of a correlation function;
• computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• and
• comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if the weaker path is detected.

An apparatus comprising a processor and a memory, the memory containing program code executable by the processor for performing the following:

• program code for obtaining a shape of a local maximum of a correlation function;
• program code for computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• and
• program code for comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if the weaker path is detected.

A computer-readable medium including program code stored thereon, comprising:

• program code for obtaining a shape of a local maximum of a correlation function;
• program code for computing a Left Edge Height Ratio Indicator (LEHRI) of the shape of the local maximum;
• and
• program code for comparing the LEHRI to a LEHRI threshold (TLEHRI) to determine if a weaker path is detected.

A method of processing positioning signals comprising:

• receiving a positioning signal;
• correlating the received positioning signal with a generated reference signal to generate correlated positioning information having a peak, wherein the correlated positioning information includes a first correlation result and a second correlation result on the same side of the peak of the correlated positioning information;
• determining a relationship between the first correlation result and the second correlation result;
• based on the relationship between the first correlation result and the second correlation result, determining whether short multipath comprising a weaker early signal and at least one stronger later signal in the positioning signal is indicated;
• and
• if short multipath is indicated, processing the correlated positioning information to remove the effect of at least some of the correlated positioning information corresponding to the at least one stronger later signal.

An apparatus comprising:

• means for receiving a positioning signal;
• means for correlating the received positioning signal with a generated reference signal to generate correlated positioning information having a peak, wherein the correlated positioning information includes a first correlation result and a second correlation result on the same side of the peak of the correlated positioning information;
• means for determining a relationship between the first correlation result and the second correlation result;
• means for determining whether short multipath comprising a weaker early signal and at least one stronger later signal in the positioning signal is indicated based on the relationship between the first correlation result and the second correlation result;
• and
• means for processing the correlated positioning information to remove the effect of at least some of the correlated positioning information corresponding to the at least one stronger later signal if short multipath is indicated.

An apparatus comprising:

• circuitry to receive a positioning signal;
• a correlator to correlate the received positioning signal with a generated reference signal to generate correlated positioning information having a peak, wherein the correlated positioning information includes a first correlation result and a second correlation result on the same side of the peak of the correlated positioning information;
• and
• control logic comprising software, firmware, hardware or a combination configured to:
• determine a relationship between the first correlation result and the second correlation result;
• determine whether short multipath comprising a weaker early signal and at least one stronger later signal in the positioning signal is indicated based on the relationship between the first correlation result and the second correlation result;
• and
• process the correlated positioning information to remove the effect of at least some of the correlated positioning information corresponding to the at least one stronger later signal if short multipath is indicated.

A computer readable medium including instructions stored thereon that, when executed, cause one or more machines to perform operations comprising:

• receiving a positioning signal data;
• correlating the received positioning signal data with reference data to generate correlated positioning data having a peak, wherein the correlated positioning data includes a first correlation result and a second correlation result on the same side of the peak of the correlated positioning data;
• determining a relationship between the first correlation result and the second correlation result;
• determining whether short multipath comprising a weaker early signal and at least one stronger later signal in the positioning signal is indicated based on the relationship between the first correlation result and the second correlation result;
• and
• processing the correlated positioning data to remove the effect of at least some of the correlated positioning data corresponding to the at least one stronger later signal if short multipath is indicated.