Global positioning system receiver

Claim 2

the global Positioning System receiver as recited in Claim 1 wherein: said receiving means comprises IF sampling means for generating said I and Q samples.

Claim 3

The Global Positioning System receiver as recited in Claim 1 wherein: said receiving means comprises baseband sampling means for generating said I and Q samples.

Claim 4

The global Positioning system receiver as recited in Claim 3 wherein: said correlator means comprises mens for correlating said I and Q samples with said IREF component of said internally generated PN-code reference.

Claim 5

The Global Positioning system receiver as recited in Claim 1 wherien said sign and magnitude input weighting means of sid correlator means comprises: register means for storing an R factor weighting input; multiplexor means coupled to said register means for selecting between weighting inside crossings of said samples and weighting outside crossings of said samples in accordance with said weighting select signal; and logic means coupled to said multiplexor means for generating said weighting select signal in accordance with sign and magnitude inputs of said samples to said logic means.

Claim 6

the Global Positioning System receiver as recited in Claim 5 wherein said multiplexor means comprises: an I weighting mutiplexor having a first input coupled to said R factor register means for selecting said weighting outside crossings, and a second input coupled to an input sample weight for selecting said weighted inside crossing; and a Q weighting multiplexor having a first input coupled to said R factor register means for selecting said weighted outside crossings and a second input coupled to said input sample weight for selecting said weighted inside crossings.

Claim 7

The Global Positioning System receiver as recited in Claim 5 wherein said logic means comprises means for performing an exclusive-OR magnitude select logic function.

Claim 8

The Global Positioning System receiver as recited in Claim 1 wherein said correlator means comprises: input weighting means for applying an R factor weighting for outside crossings to said samples thereby providing said weighted samples with additional A/D conversion gain for correlation; adder control means coupled to said input weighting means for determining whether each of said weighted samples is added to or subtracted from an accumulated value of said weighting samples in accordance with a correlator control signal; means for generating said correlator control signal by comparing a sign of said sample to a PN-code reference signal; and intergrator means coupled to said adder control means and said correlator control signal generating means for accumulating and integrating said weighted samples over a correlation time interval.

Claim 9

the Global Positioning System as recited in Claim 8 wherein said generating means comprises means for performing an exclusive-OR correlator control logic function.

Claim 10

A Global Positioning System receiver comprising: receiving means for performing sampling of a received PN-code modulated carrier to generate in-phase (I) and quadrature-phase (Q) samples; signal processor means, coupled to outputs of said receiving means, having a plularity of channels, each of said channels comprising: (a) means for removing received carrier doppler from said in-phase (I) and quadrature-phase (Q) samples; (b) means for generating a PN-code reference which is a replica of said received PN-code, said PN-code reference having an in-phase (IREF) component and a quadrature-phase (QREF) component;. (c) means, coupled to said carrier doppler removing means and said PN-code reference replica generating means, for correlating said I and Q samples with said IREF and QREF components respectively of said replicated PN-code; (d) said corrlating means comprises sign and magnitude input weighting of said I and Q samples including an I input weighting means coupled to a plurality of I multi-Y-tap correlator/integrators and a Q input weighting means coupled to a plurality of Q multi-Y-tap correlator/ integrators, each of said input weighting means being controlled in accordance with a weighting select input; and means coupled to said signal processor means for processing said correlated I and Q samples to determine the phase of said carrier signals, to provide multi-channel control signals to said signal processor means and to estimate a pseudo-range and pseudo-range rate.

Claim 11

The apparatus as recited in Claim 10 wherein said I input weghting means comprises a register means for storing an R factor weighting input.

Claim 12

The apparatus as recited in Claim 11 wherein said R factor weighting input is variable under programmed control.

Claim 13

The apparatus as recited in Claim 11 wherein said R factor weighting input is a constant for a specific correlation interval (t cj ).

Claim 14

The Global Positioning System receiver as recited in Claim 10 wherein: said receiving means comprises IF sampling means.

Claim 15

The Global Positoning System receiver as recited in Claim 10 wherein: said receiving means comprises basband sampling means.

Claim 16

The Global positioning system receiver as recited in Claim 15 wherein: said corrlator means comprises means for correlating said I and Q samples with said IREF component of said internally generated PN-code reference.

Claim 17

A correlation apparatus comprising: means for removing received carrier doppler from in-phase (I) and quadrature-phase (Q) samples of a received pseudo-random noise (PN) codde modulated carrier signal; means coupled to said received carrier doppler removing means for generating a PN-code reference which is a replica of said received PN-code, said PN-code reference having an in-phase (IREF) component and a quadrature-phase (QREF) component; and means, coupled to said carrier doppler removing means ans said PN-code reference replica generating means, for correlating said I and Q samples with said IREF and QREF components respectively of said replicated PN-code.

Claim 18

The correlation apparatus apparatus as recited in Claim 17 wherein said correlating means comprises sign and magnitude input weighting of said I and Q samples.

Claim 19

The correlation apparatus as recited in Claim 18 wherein said sign and magnitude input weighting comprises: register means for storing an R factor weighting input; multiplexor means coupled to said register means for selecting between weighted inside crossings of said samplkes and weighted outside crossings of said samples in accordance with said weitghting select signal; and logic means coupled to said multiplexor means for generating said weitghting select signal in accordance with sign and magnitude inputs of said samples to said logic means.

Claim 20

The correlation apparatus as recited in Claim 19 wherein said logic means comprises means for performing an exclusive-OR magnitude select logic function.

Claim 21

The correlation apparatus as recited in Claim 17 wherein said correlating means comprises: input weighting means for applying an R factor weighting for outside crossings to said samples thereby providing said weighted samples with additional A/D conversion gain for correlation; adder control means coupled to said input weighting means for determining whether each of said weighted samples is added to or substracted from an accumulated value of said weighted samples in accordance with a correlator control signal; means for generating said correlator control signal by comprising a sign of said I and Q to a PN-code reference signal; and integrator means coupled to said adder control means and said correlator control signal generating means dor accumulating and integrating said weighted samples over a correlation time interval.

Claim 22

The correlation apparatus as recited in Claim 20 wherein said generating means comprises means for performing an exclusive-OR correlation control logic function.

Claim 23

The correlation apparatus as recited in Claim 17 wherein: said correlating means comprises an I input weighting means coupled to a plurality of I multi-Y-tap correlator/integrators and Q input weighting means coupled to a plurality of Q multi-Y-tap correlator/integrators, each of said input weighting means being controlled in accordance with a weighting select input.

Claim 24

The correlation apparatus as recited in Claim 23 wherein said I input weighting means comprises a register means for storing an R factor weighting input.

Claim 25

The correlation apparatus as recited in Claim 24 wherein said R factor weighting input is variable under programmed control.

Claim 26

the correlation apparatus as recited in Claim 24 wherein said R factor weighting input is a constant for a specific correlation interval (T cj).

Claim 27

the correlation apparatus as recited in Claim 23 wherein said correlating means comprises logic means for generating said weighting select input in accordance with sign and magnitude inputs of said I samples provided to a first of sid logic means coupled to said I input weighting means and sign and magnitude inputs of said Q samples provided to a second od said logic means coupled to said Q input weighting means.

Claim 29

The method as recited in Claim 28 wherein said step of said sampling in a receiver means includes said receiver performing IF sampling for generating said I and Q samples.

Claim 30

The method as recited in Claim 28 wherein said step of sampling in a receiver means includes said receiver means performing baseband sampling for generating said I and Q samples.

Claim 31

the method as recited in Claim 30 wherein said step of correlating further comprises the step of correlating said weighted I and Q samples with only said IREF component of said internally generated PN-code reference when performing said baseband sampling in said receiver means.

Claim 33

The method as recited in Claim 32 wherein said step of corelating said I and Q samples said IREF and QREF components comprises coupling an I input weighting means to a plurality of I multi-Y-tap correlator/integrators and coupling a Q input weighting means to a plurality of Q multi-Y-tap correlator/intagrators, each of said I or Q input weighting means being controlled in accordance with an I or Q weighting select input.

Claim 34

The method as recited in Claim 33 wherein said correlating step further comprises the step providing a variable R factor weighting value under programmed control.

Claim 35

The method as recited in Claim 33 wherein said correlating step further comprises the step of providing a constant R factor weighting value for a specific correlation interval (T cj ).