Chip, receiver and method for satellite signal tracking

Abstract

The present application discloses a chip, a receiver and a method for satellite signal tracking. The chip for satellite signal tracking includes: a signal tracking channel, which at least receives an input signal, a carrier frequency and a pseudo code phase; the signal tracking channel includes a carrier tracking loop; a pseudo code tracking loop; and a signal path, which includes one or more branches, at least one of which includes a first-level coherent accumulation unit, which receives an input signal stripped of a carrier and a pseudo code, processes it and obtains an observation; and also includes a complex square unit and a polarity decision unit, the former performs a complex square operation on the output of the first-level coherent accumulation unit, and the latter performs a polarity decision on the operation result of the first-level coherent accumulation unit of at least one branch. The present application enables a GNSS receiver to process satellite signals including those without pilot components and with a high transmission rate, obtain more available observations, and enhance the reliability and stability of the GNSS receiver.

Description

Technical Field

[0001] The present application relates to the field of satellite navigation technology, and in particular to a chip, a receiver and a method for satellite signal tracking. Background Art

[0002] The Global Navigation Satellite System (GNSS) can provide high-precision positioning, navigation and timing services to users on the Earth's surface and in near-Earth space, and is widely used in the fields of automobile driving, aerospace, communications, and measurement. Each satellite navigation system has multiple frequencies, and broadcasts satellite signals to the ground continuously and uninterruptedly around the clock. In the field of satellite navigation technology, GNSS receivers are an important part of GNSS technology, responsible for receiving signals from satellites and calculating user positions and time. GNSS receivers that support multi-frequency signals can provide high-quality positioning, speed measurement and timing services, and realize functions such as precise single-point positioning, RTK technology, and anti-interference.

[0003] Generally, satellite signals include pilot components to improve the accuracy of GNSS receiver signal processing. However, there are still some satellite signals without pilot components and with higher data transmission rates, which makes it more difficult for GNSS receivers to capture and track these satellite signals, resulting in limited applications of these satellite signals. Summary of the invention

[0004] In response to the problems existing in the prior art, the present application proposes a chip for satellite signal tracking, comprising: a signal tracking channel, configured to at least receive an input signal, a carrier frequency and a pseudo-code phase; wherein the signal tracking channel includes a carrier tracking loop, configured to perform carrier synchronization and stripping on the input signal; a pseudo-code tracking loop, configured to perform pseudo-code synchronization and stripping on the input signal stripped of the carrier; and a signal path, comprising one or more branches, wherein at least one of the branches includes a first-level coherent accumulation unit, configured to receive the input signal stripped of the carrier and the pseudo-code, process it and obtain an observed value; and also includes a complex squaring unit and a polarity decision unit, wherein the complex squaring unit is configured to perform a complex squaring operation on the output of the first-level coherent accumulation unit, and the polarity decision unit is configured to perform a polarity decision on the operation result of the first-level coherent accumulation unit of at least one of the branches.

[0005] In particular, the chip, wherein the signal path also includes a mixer, coupled to the carrier tracking loop of the signal tracking channel, configured to receive the input signal and the local carrier output by the carrier tracking loop and perform mixing; and wherein at least one of the branches also includes a first correlator, coupled to the mixer and the pseudo-code tracking loop of the signal tracking channel, configured to receive the output of the mixer and the local pseudo-code output by the pseudo-code tracking loop and perform correlation operations to obtain correlation values; the first-level coherent accumulation unit, coupled to the first correlator, configured to receive the correlation value output by the first correlator and perform coherent accumulation; the complex square unit, coupled to the first-level coherent accumulation unit.

[0006] In particular, in the chip, when the code sequence output by the pseudo-code tracking loop includes E, P, and L code sequences, the signal path includes three branches: E, P, and L.

[0007] In particular, the chip, wherein the polarity decision unit in the signal path is coupled to the first-level coherent accumulation unit of the P branch of the signal path, is configured to receive the output of the first-level coherent accumulation unit of the P branch and perform polarity decision.

[0008] In particular, the chip, wherein at least one of the branches also includes a second correlator, coupled with the first-level coherent accumulation unit and the polarity decision unit, configured to receive the coherent accumulation result output by the first-level coherent accumulation unit and the polarity decision result output by the polarity decision unit and perform correlation operations.

[0009] In particular, the chip, wherein, when the signal-to-noise ratio of the signal tracking channel is greater than or equal to 5dB, the observation value is obtained based on the operation result of the second correlator; when the signal-to-noise ratio of the signal tracking channel is less than 5dB, the observation value is obtained based on the operation result of the complex square unit.

[0010] In particular, the chip, wherein the branch also includes a first multiplexing unit, coupled to the complex square unit and the second correlator, configured to output the received operation result of the complex square unit or the operation result of the second correlator.

[0011] In particular, the chip, wherein the branch of the signal path also includes a second-level coherent accumulation unit, coupled to the first multiplexing unit, configured to receive the complex square operation result from the complex square unit output by the first multiplexing unit or the operation result of the second correlator, and perform coherent accumulation.

[0012] The present application also relates to a receiver for satellite signal tracking, including a chip for satellite signal tracking as described above.

[0013] The present application also relates to a method for satellite signal tracking, comprising stripping a carrier and a pseudo code from an input signal; performing a first-level coherent accumulation operation on the input signal stripped of the carrier and the pseudo code; performing a complex square operation on the result of the first-level coherent accumulation operation; performing a polarity decision on the result of the first-level coherent accumulation operation; and providing the complex square operation result and the polarity decision result to subsequent operations to obtain an observation value.

[0014] In particular, in the method described, when obtaining the observed value based on the polarity decision result, the first-level coherent accumulation operation result is correlated with the polarity decision result, and the observed value is obtained based on the result of the correlation operation.

[0015] In particular, the method further includes, when the signal-to-noise ratio is less than 5 dB, obtaining the observation value based on the complex square operation result; when the signal-to-noise ratio is greater than or equal to 5 dB, obtaining the observation value based on the polarity decision operation result.

[0016] The present application enables a GNSS receiver to process satellite signals including those without pilot components and with a high transmission rate, obtain more available observation quantities, and enhance the reliability and stability of the GNSS receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Below, the preferred embodiments of the present application will be further described in detail with reference to the accompanying drawings, wherein:

[0018] Figure 1 FIG. 1 is a schematic diagram of the structure of a GNSS receiver according to an embodiment of the present application;

[0019] Figure 2 The figure is a schematic diagram of the structure of a signal tracking channel of a satellite signal processing chip according to an embodiment of the present application;

[0020] Figure 3 The figure shows the relationship between the bit error rate and the signal-to-noise ratio of an equal-probability binary bipolar signal according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] In the following detailed description, reference may be made to the various specification drawings that are part of the present application and are used to illustrate specific embodiments of the present application. In the accompanying drawings, similar reference numerals describe substantially similar components in different figures. The various specific embodiments of the present application are described below in sufficient detail so that a person of ordinary skill in the art with relevant knowledge and skills in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be used or structural, logical or electrical changes may be made to the embodiments of the present application.

[0023] The technologies, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and devices should be considered as part of the specification. The connection between the units in the drawings is only for the convenience of explanation, which means that at least the units at both ends of the connection are communicating with each other, and is not intended to limit the unconnected units to be unable to communicate. In addition, the number of lines between two units is intended to indicate at least the number of signals involved in the communication between the two units or at least the output terminals, and is not intended to limit the two units to only communicate with the signals shown in the figure.

[0024] The present application proposes a chip for satellite signal tracking, so that a GNSS receiver using the chip can process satellite signals including those without pilot components and with a high transmission rate, obtain more available observation quantities, improve the service quality of the GNSS receiver, and further enhance the reliability, sensitivity and stability of the receiver.

[0025] Figure 1 FIG. 4 is a schematic diagram of the structure of a GNSS receiver according to an embodiment of the present application.

[0026] According to one embodiment, the GNSS receiver includes an antenna 11 , a frequency mixing and sampling module 12 , an intermediate frequency stripping module 13 and a down-sampling module 14 .

[0027] According to one embodiment, the antenna 11 is configured to receive radio frequency signals transmitted by a satellite.

[0028] According to one embodiment, the frequency mixing sampling module 12 is coupled to the antenna 11. The frequency mixing sampling module 12 is configured to receive the RF signal transmitted by the antenna 11, convert the RF signal into an intermediate frequency sampling signal after processing by a pre-filter, an amplifier, analog down-conversion, A / D sampling, etc., and output the signal. One RF signal corresponds to one intermediate frequency sampling signal.

[0029] According to one embodiment, the intermediate frequency stripping module 13 is coupled to the mixing sampling module 12. The intermediate frequency stripping module 13 is configured to receive the intermediate frequency sampling signal output by the mixing sampling module 12, pre-process the intermediate frequency sampling signal, and down-convert the intermediate frequency sampling signals of different frequency points to low intermediate frequency or zero intermediate frequency respectively.

[0030] According to one embodiment, the downsampling module 14 is coupled to the IF stripping module 13. The downsampling module 14 is configured to receive the output of the IF stripping module 13 and perform downsampling processing on the output of the IF stripping module 13 to reduce the sampling frequency to reduce the subsequent baseband signal calculation amount.

[0031] According to one embodiment, the GNSS receiver further includes a capture module 15 coupled to the downsampling module 14. The capture module 15 is configured to receive the output of the downsampling module 14, detect and analyze the output of the downsampling module 14, identify satellite signals, and obtain a rough pseudo code phase and carrier frequency. In one embodiment, the output of the downsampling module 14 may include a digital intermediate frequency signal.

[0032] According to one embodiment, the GNSS receiver further includes a noise statistics module 16 coupled to the downsampling module 14. The noise statistics module 16 is configured to obtain, for example, a digital intermediate frequency signal output by the downsampling module 14, perform noise power estimation on the output of the downsampling module 14, and thereby evaluate the quality of the satellite signal. The noise statistics module 16 may include a plurality of noise estimation channels, each of which estimates, for example, a digital intermediate frequency signal output by the downsampling module 14 to obtain noise power.

[0033] According to one embodiment, the GNSS receiver further includes a tracking module 17 coupled to the downsampling module 14, the capture module 15, and the noise statistics module 16. The tracking module 17 is configured to receive the output of the downsampling module 14 and the carrier frequency and pseudo code phase output by the capture module 15, as well as the noise power from the noise statistics module 16, and achieve synchronization locking of the satellite signal by finely reproducing the local carrier and pseudo code, thereby achieving complete stripping of the satellite signal and stably outputting observation quantities such as code phase and carrier phase.

[0034] According to one embodiment, the GNSS receiver further includes a PVT solution module 18 coupled to the tracking module 17. The PVT solution module 18 is configured to receive the observations output by the tracking module 17, solve the observations and obtain the receiver position, velocity and time information.

[0035] According to one embodiment, the GNSS receiver includes a satellite signal processing chip, wherein the satellite signal processing chip may include a capture module 15, a noise statistics module 16, and a tracking module 17. In one embodiment, the tracking module 17 includes a plurality of signal tracking channels, each of which tracks, for example, a digital intermediate frequency signal output by the downsampling module 14 at the same frequency point. For different satellite signals, the tracking channel uses different pseudo code sequences to perform pseudo code synchronization on the output of the downsampling module 14.

[0036] Figure 2 The figure is a schematic diagram of the structure of the signal tracking channel of the satellite signal processing chip according to one embodiment of the present application. Figure 2 As shown, the signal tracking channel may include at least a signal path 271, and a carrier tracking loop 272 and a pseudo code tracking loop 273 coupled to the signal path 271. The signal path 271 includes three branches, namely, E, P, and L. In different application scenarios and requirements, the number of branches included in the signal path 271 is different, and the signal path 271 includes at least one branch. When the number of branches is greater than three, it is more conducive to multipath suppression, anti-forwarding interference, BOC signal tracking, etc.

[0037] According to one embodiment of the present application, the carrier tracking loop 272 is coupled to the P branch in the signal path 271, and is configured to receive the carrier frequency and the output of the P branch of the signal path 271, reproduce the local carrier based on the carrier frequency and the output of the P branch, and feed it back to the signal path 271.

[0038] According to one embodiment, the pseudo code tracking loop 273 is coupled to the three branches P, E, and L in the signal path 271, respectively, and is configured to receive the pseudo code phase and the outputs from the three branches P, E, and L of the signal path 271, reproduce the local pseudo code based on the pseudo code phase and the outputs of the three branches P, E, and L of the signal path 271, and feed it back to the signal path 271. The local pseudo code reproduced by the pseudo code tracking loop 273 includes, for example, an E code sequence, a P code sequence, and an L code sequence, and the three code sequences are output independently.

[0039] According to one embodiment, the carrier tracking loop 272 includes a carrier phase discriminator, a carrier loop filter, and a carrier NCO. The pseudo code tracking loop 273 includes a non-coherent accumulation unit, a code phase discriminator, and a spread spectrum code generator. According to one embodiment, the non-coherent accumulation unit in the pseudo code tracking loop 273 can increase the coherent accumulation time and improve the code phase tracking performance. According to one embodiment, the code phase discriminator is configured to track and detect the estimated code phase error, and the obtained code phase error is input into the code loop filter for smoothing filtering to eliminate burrs, and the smoothed control signal is input into the spread spectrum code generator to control the code sequence generation rate. According to one embodiment, the code phase discriminator uses the outputs of the three branches E, P, and L to estimate the code phase error.

[0040] According to one embodiment, the signal path 271 is coupled with the carrier tracking loop 272 and the pseudo code tracking loop 273. The signal path 271 is configured to receive at least the local carrier output by the carrier tracking loop 272, the local pseudo code output by the pseudo code tracking loop 273, and the input signal, and synchronize the input signal with the local pseudo code and the local carrier, thereby stripping the carrier and pseudo code from the input signal. The input signal may be, for example, a digital intermediate frequency signal output by the downsampling module 14.

[0041] According to one embodiment, the signal path 271 includes a mixer 27101 coupled to the carrier tracking loop 272. The mixer 27101 is configured to receive an input signal and a local carrier output by the carrier tracking loop 272, mix the input signal with the local carrier output by the carrier tracking loop 272, synchronize and lock the input signal with the local carrier, and obtain and output the input signal stripped of the carrier.

[0042] According to one embodiment, the P branch of the signal path 271 includes a correlator 27102 coupled to the pseudo code tracking loop 273 and the mixer 27101. The E branch of the signal path 271 includes a correlator 27112 coupled to the pseudo code tracking loop 273 and the mixer 27101. The L branch of the signal path 271 includes a correlator 27122 coupled to the pseudo code tracking loop 273 and the mixer 27101. The correlator 27102, the correlator 27112 and the correlator 27122 are configured to respectively receive the signal stripped of the carrier output by the mixer 27101 and the corresponding code sequence output by the pseudo code tracking loop 273, and perform correlation operation on the signal stripped of the carrier and the corresponding code sequence, so as to realize pseudo code stripping of the input signal stripped of the carrier, and obtain multiple correlation values ​​of the E, P and L branches.

[0043] According to one embodiment, the P branch of the signal path 271 further includes a first-stage coherent accumulation unit 27103 coupled to the correlator 27102. The first-stage coherent accumulation unit 27103 is configured to receive multiple P branch correlation values ​​output by the correlator 27102, and perform coherent accumulation of the multiple P branch correlation values ​​per unit time length. The unit time length may be, for example, 1 ms, 2 ms, etc.

[0044] According to one embodiment, the first-stage coherent accumulation unit 27103 The sub-coherent accumulation result can be modeled as

[0045] (1)

[0046] in, is the correlation amplitude, , is the sampling rate; is a data bit level value with a value of +1 or -1; is the Doppler frequency, which is assumed to remain unchanged during a tracking update; is the coherent accumulation time, which can be an integer multiple of 1ms; is the phase; and are the in-phase and quadrature component noises respectively. n is an integer greater than or equal to 1.

[0047] According to one embodiment, the P branch of the signal path 271 further includes a complex square unit 27104 coupled to the first-stage coherent accumulation unit 27103. The complex square unit 27104 is configured to receive the first-stage coherent accumulation result of the P branch output by the first-stage coherent accumulation unit 27103, and perform a complex square operation on the first-stage coherent accumulation result of the P branch. According to one embodiment, the result of the complex square operation can be modeled as

[0048] (2)

[0049] in, and are the squares of the in-phase and quadrature component noise, respectively.

[0050] In the signal tracking channel of the GNSS receiver, the square of the complex number is used to eliminate the bit effect of data transmission, which increases the total time of the subsequent coherent accumulation operation. When the signal is weak, the coherent integration gain is increased to improve the quality of the satellite signal and enhance the sensitivity of the receiver.

[0051] According to one embodiment, the signal path 271 may further include a polarity decision unit 27131. The polarity decision unit 27131 may be coupled to the first-stage coherent accumulation unit 27103 in the P branch, and configured to receive the first-stage coherent accumulation result of the P branch output by the first-stage coherent accumulation unit 27103, and perform polarity decision based on the output of the first-stage coherent accumulation unit 27103 to obtain a polarity decision result. The polarity decision result is obtained by performing polarity decision on the output of the first-stage coherent accumulation unit, and the phase of the input signal is adjusted using the result of the polarity decision, thereby achieving long-term coherent accumulation, improving the tracking performance of the signal tracking channel, and obtaining high-quality observations.

[0052] According to one embodiment, the P branch of the signal path 271 also includes a correlator 27107 coupled to the polarity decision unit 27131 and the first coherent accumulation unit 27103, configured to receive the first-level coherent accumulation result of the P branch output by the first-level coherent accumulation unit 27103 and the polarity decision result output by the polarity decision unit 27131, and perform correlation operations on the first-level coherent accumulation result of the P branch and the polarity decision result.

[0053] According to one embodiment, for different satellite signals, the GNSS receiver processor controls the state of the polarity decision unit 27131. When the polarity decision unit is in a failed state, the output of the polarity decision unit is 1, and the output of the correlator 27107 is the first-stage coherent accumulation result of the P branch.

[0054] According to one embodiment, the P branch of the signal path 271 may further include a multiplexing unit 27105 coupled to the complex square unit 27104 and the correlator 27107. The multiplexing unit 27105 is configured to output the complex square operation result output by the complex square unit 27104 or the output of the correlator 27107.

[0055] According to one embodiment, the P branch of the signal path 271 may further include a second-stage coherent accumulation unit 27106 coupled to the multiplexing unit 27105. The second-stage coherent accumulation unit 27106 is configured to perform a coherent accumulation operation on the output of the complex square unit 27104 or the output of the correlator 27107 received from the multiplexing unit 27105.

[0056] In one embodiment, when the signal tracking channel is an additive white Gaussian noise channel, the bit error rate of the coherent accumulation result output by the first-stage coherent accumulation unit in the signal tracking channel is SNR The relationships are

[0057] (3)

[0058] (4)

[0059] Figure 3 The figure shows the relationship between the bit error rate and the signal-to-noise ratio of an equal probability binary bipolar signal according to an embodiment of the present application, wherein the signal tracking channel is an additive white Gaussian noise channel. Figure 3 The horizontal axis represents the signal-to-noise ratio of the signal tracking channel, and the vertical axis represents the bit error rate of the equal probability binary bipolar signal transmission. When the bit error rate is 4dB, is 0.0125008; when the signal-to-noise ratio When the bit error rate is 5dB, As shown in the figure, the signal-to-noise ratio of the signal tracking channel When the bit error rate is greater than 5dB Less than 1%.

[0060] In one embodiment, the polarity decision threshold is set to 5 dB. The signal tracking channel is controlled by the GNSS receiver processor. When the signal-to-noise ratio is greater than or equal to 5 dB, the polarity decision unit receives the output of the first-stage coherent accumulation unit in the P branch and makes a polarity decision. When the value is less than 5 dB, the complex square unit performs a complex square operation on the output of the first-stage coherent accumulation unit. The polarity decision unit is in a failed state, and the output of the correlator 27107 is the output of the first-stage coherent accumulation unit 27103.

[0061] According to one embodiment of the present application, the E branch and the L branch of the signal path 271 may also respectively include structures similar to the P branch.

[0062] According to one embodiment, the E branch of the signal path 271 includes a first-level coherent accumulation unit 27113 coupled to the correlator 27112, a correlator 27117 coupled to the first-level coherent accumulation unit 27113 and the polarity decision unit 27131, and a complex square unit 27114 coupled to the first-level coherent accumulation unit 27113. The first-level coherent accumulation unit 27113 is configured to receive a plurality of E branch correlation values ​​output by the correlator 27112 and perform a coherent accumulation operation to obtain a first-level coherent accumulation result of the E branch. The correlator 27117 is configured to receive the first-level coherent accumulation result of the E branch output by the first-level coherent accumulation unit 27113 and the polarity decision result output by the polarity decision unit 27131, and perform a correlation operation on the first-level coherent accumulation result of the E branch and the polarity decision result. The complex square unit 27114 is configured to perform a complex square operation on the output of the first-stage coherent accumulation unit 27113 .

[0063] According to one embodiment, the E branch of the signal path 271 further includes a multiplexing unit 27115 coupled to the complex square unit 27114 and the correlator 27117, and a second-stage coherent accumulation unit 27116 coupled to the multiplexing unit 27115. The multiplexing unit 27115 is configured to output the complex square operation result of the complex square unit 27114 or the output of the correlator 27117. The second-stage coherent accumulation unit 27116 is configured to receive the output of the multiplexing unit 27117 and perform a coherent accumulation operation.

[0064] According to one embodiment, the L branch of the signal path 271 includes a first-level coherent accumulation unit 27123 coupled to the correlator 27122, a correlator 27127 coupled to the first-level coherent accumulation unit 27123 and the polarity decision unit 27131, and a complex square unit 27124 coupled to the first-level coherent accumulation unit 27123. The first-level coherent accumulation unit 27123 is configured to receive a plurality of L branch correlation values ​​output by the correlator 27122 and perform a coherent accumulation operation to obtain a first-level coherent accumulation result of the L branch. The correlator 27127 is configured to receive the first-level coherent accumulation result of the L branch output by the first-level coherent accumulation unit 27123 and the polarity decision result output by the polarity decision unit 27131, and perform a correlation operation on the first-level coherent accumulation result of the L branch and the polarity decision result. The complex squaring unit 27124 is configured to perform a complex squaring operation on the output of the first-stage coherent accumulation unit 27123 .

[0065] According to one embodiment, the L branch of the signal path 271 further includes a multiplexing unit 27125 coupled to the complex square unit 27124 and the correlator 27127, and a second-stage coherent accumulation unit 27126 coupled to the multiplexing unit 27125. The multiplexing unit 27125 is configured to output the complex square operation result of the complex square unit 27124 or the output of the correlator 27127. The second-stage coherent accumulation unit 27126 is configured to receive the output of the multiplexing unit 27127 and perform a coherent accumulation operation.

[0066] According to one embodiment, the complex square unit and polarity decision unit in the E and L branches of the signal path 271 and the complex square unit and polarity decision unit in the P branch may have the same settings.

[0067] For GNSS receiver chips that have both complex square units and polarity decision units, when the satellite signal is weak, the complex square unit is used to eliminate the impact of data transmission bits, and the processing gain can be improved through long-term accumulation. When the signal is strong, the result of polarity decision is used to provide more high-quality observations for RTK, PPP, etc.

[0068] The present application also includes a satellite signal processing method. According to one embodiment, the method can be executed by a satellite signal processing chip to process the input signal and obtain an observation value. Specifically, the method can include the following steps.

[0069] Step 401: Mix the input signal with the local carrier to obtain the input signal with the carrier stripped off.

[0070] Step 402, performing a correlation operation on the input signal stripped of the carrier and the local pseudo code to obtain the input signal stripped of the carrier and the pseudo code.

[0071] According to an embodiment, the input signal received by the satellite processing chip may be a digital intermediate frequency signal from a down-sampling module. The input signal is synchronously locked using the reproduced local carrier and pseudo code to achieve separation of the carrier and pseudo code.

[0072] Step 403: perform a first-level coherent accumulation operation on the input signal stripped of the carrier and the pseudo code.

[0073] According to an embodiment, the reproduced local pseudo code may include three code sequences: E, P, and L. The carrier-stripped input signal may be correlated with the three code sequences E, P, and L respectively to obtain correlation values ​​corresponding to the three code sequences E, P, and L.

[0074] According to one embodiment, a first-level coherent accumulation operation is performed on a plurality of correlation values ​​corresponding to the three code sequences E, P, and L, respectively, to obtain coherent accumulation results corresponding to the three code sequences E, P, and L.

[0075] Step 404, complex squaring the result of the first-stage coherent accumulation operation.

[0076] Step 405, performing polarity determination on the result of the first-stage coherent accumulation operation.

[0077] Step 406: Provide the complex number square operation result and the polarity judgment result to subsequent operations to obtain an observation value.

[0078] According to one embodiment, when the signal-to-noise ratio SNR is less than 5 dB, the observation value is obtained based on the complex square operation result. According to another embodiment, when the signal-to-noise ratio is greater than or equal to 5 dB, the first-level coherent accumulation operation result is correlated with the polarity decision result, and the observation value is obtained based on the result of the correlation operation.

[0079] The satellite signal processing chip for signal tracking proposed in the present application can not only process signals with slower data transmission rates, such as 100bps B1C signals and 50bps MEO B1I signals, but is also suitable for signals with higher transmission data rates, such as 500bps GEO B1I signals, 1000bps B2b signals, and even higher-rate S1 and S2C signals, etc., and can effectively improve the tracking performance of these signals of GNSS receivers, has strong versatility and greatly improves the sensitivity of GNSS receivers.

[0080] The present application also provides a receiver for satellite signal tracking, comprising any satellite signal processing chip as described above.

[0081] The above embodiments are only used to illustrate the present application, and are not intended to limit the present application. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the scope of the present application. Therefore, all equivalent technical solutions should also fall within the scope disclosed in the present application.

Claims

1. Chips used for satellite signal tracking, including: A signal tracking channel configured to receive at least an input signal, a carrier frequency and a pseudo code phase; wherein the signal tracking channel includes, A carrier tracking loop configured to perform carrier synchronization and stripping on the input signal; a pseudo code tracking loop configured to perform pseudo code synchronization and stripping on the input signal stripped of the carrier; and A signal path, comprising one or more branches, wherein at least one of the branches comprises a first-stage coherent accumulation unit, configured to receive the input signal stripped of the carrier and the pseudo code, process the input signal and obtain an observed value; and further comprising a complex square unit and a polarity decision unit, wherein the complex square unit is configured to perform a complex square operation on the output of the first-stage coherent accumulation unit, and the polarity decision unit is configured to perform a polarity decision on the operation result of the first-stage coherent accumulation unit of at least one of the branches; The signal path further comprises a mixer, coupled to the carrier tracking loop of the signal tracking channel, configured to receive the input signal and the local carrier output by the carrier tracking loop and perform mixing; and Wherein, at least one of the branches further comprises: A first correlator is coupled to the mixer and the pseudo code tracking loop of the signal tracking channel, and is configured to receive the output of the mixer and the local pseudo code output by the pseudo code tracking loop and perform correlation operations to obtain a correlation value; The first-stage coherent accumulation unit is coupled to the first correlator and configured to receive the correlation value output by the first correlator and perform coherent accumulation; The complex square unit is coupled to the first-stage coherent accumulation unit; When the code sequence output by the pseudo code tracking loop includes E, P, and L code sequences, the signal path includes three branches: E, P, and L; The polarity decision unit in the signal path is coupled to the first-stage coherent accumulation unit of the P branch of the signal path, and is configured to receive the output of the first-stage coherent accumulation unit of the P branch and perform polarity decision.

2. The chip according to claim 1, wherein: At least one of the branches also includes The second correlator is coupled to the first-stage coherent accumulation unit and the polarity decision unit, and is configured to receive the coherent accumulation result output by the first-stage coherent accumulation unit and the polarity decision result output by the polarity decision unit and perform correlation operation.

3. The chip according to claim 2, wherein: When the signal-to-noise ratio of the signal tracking channel is greater than or equal to 5 dB, the observed value is obtained based on the operation result of the second correlator; When the signal-to-noise ratio of the signal tracking channel is less than 5 dB, the observation amount is obtained based on the calculation result of the complex square unit.

4. The chip according to claim 3, wherein: The branch also includes The first multiplexing unit is coupled to the complex square unit and the second correlator, and is configured to output the received operation result of the complex square unit or the operation result of the second correlator.

5. The chip according to claim 4, wherein: The branch of the signal path also includes The second-stage coherent accumulation unit is coupled to the first multiplexing unit and is configured to receive the complex square operation result from the complex square unit or the operation result of the second correlator output by the first multiplexing unit and perform coherent accumulation.

6. A receiver for satellite signal tracking, comprising the chip for satellite signal tracking as claimed in any one of claims 1 to 5.

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