Chip, receiver and method for improving satellite signal carrier-to-noise ratio

Abstract

The present application discloses a chip, a receiver and a method for improving the carrier-to-noise ratio of a satellite signal. The chip includes a carrier-to-noise ratio estimation module, and a signal tracking channel includes: a first coherent accumulation unit; a polarity decision unit, which receives the output of the first coherent accumulation unit and performs polarity decision; a first correlation unit; a second coherent accumulation unit, which performs coherent accumulation operation based on the output of the polarity decision unit; a broadband energy statistics unit, which performs statistical estimation on the output of the first coherent accumulation unit to obtain a broadband energy statistical estimation value; a narrowband energy statistics unit, which performs statistical estimation on the output of the second coherent accumulation unit to obtain a narrowband energy statistical estimation value; a carrier-to-noise ratio calculation unit, which is coupled with the broadband energy statistics unit and the narrowband energy statistics unit, and receives the broadband energy statistical estimation value and / or the narrowband energy statistical estimation value. The present application improves the performance of the carrier-to-noise ratio and carrier-to-noise ratio redundancy of a GNSS receiver and the positioning and navigation capabilities.

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 improving the carrier-to-noise ratio of a satellite signal. Background Art

[0002] The Global Navigation Satellite System (GNSS) can provide high-precision positioning, navigation and timing services for 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. 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] The carrier-to-noise ratio is an important parameter for the working performance of GNSS receivers. GNSS receivers use the carrier-to-noise ratio to evaluate the quality of satellite signals and the performance of signal tracking channels, and switch and schedule the tracking strategy and mode of GNSS receivers based on the carrier-to-noise ratio. Traditional GNSS receivers allocate signal tracking channels and corresponding noise estimation channels to satellite signals at each frequency point, thereby obtaining the carrier-to-noise ratio of the signal at that frequency point. However, for satellite signals without pilot components and with high data transmission rates, for example, the signal acquisition and tracking performance of GNSS receivers is poor, which in turn affects the carrier-to-noise ratio performance, resulting in limited applications of these satellite signals. Summary of the invention

[0004] In view of the problems existing in the prior art, the present application proposes a chip for improving the carrier-to-noise ratio of a satellite signal, including a carrier-to-noise ratio estimation module, which includes a signal tracking channel; the signal tracking channel includes: a first coherent accumulation unit, configured to receive an input signal stripped of a carrier and a pseudo code and perform a coherent accumulation operation on the input signal; A polarity decision unit, coupled to the first coherent accumulation unit, configured to receive the output of the first coherent accumulation unit and perform polarity decision; a first correlation unit, coupled to the first coherent accumulation unit and the polarity decision unit, configured to receive the output of the first coherent accumulation unit and the polarity decision unit and perform correlation operation on the two; a second coherent accumulation unit, configured to perform coherent accumulation operation based on the output of the polarity decision unit; a broadband energy statistics unit, coupled to the first coherent accumulation unit, configured to perform statistical estimation on the output from the first coherent accumulation unit to obtain a broadband energy statistical estimation value; a narrowband energy statistics unit, coupled to the second coherent accumulation unit, configured to perform statistical estimation on the output from the second coherent accumulation unit to obtain a narrowband energy statistical estimation value; a carrier-to-noise ratio calculation unit, coupled to the broadband energy statistics unit and the narrowband energy statistics unit, configured to receive the broadband energy statistical estimation value and / or the narrowband energy statistical estimation value.

[0005] In particular, in the chip, when the signal-to-noise ratio is greater than or equal to 5 dB, the narrowband energy statistics unit is configured to obtain the narrowband energy statistics estimation value based on the polarity judgment result of the polarity judgment unit.

[0006] In particular, in the chip, the carrier-to-noise ratio calculation unit is configured to obtain a first carrier-to-noise ratio based on the wideband energy statistical estimation value and the narrowband energy statistical estimation value.

[0007] In particular, the chip further includes a noise estimation channel, configured to perform noise power estimation on the input signal and obtain noise power, and output the noise power to the carrier-to-noise ratio calculation unit of the carrier-to-noise ratio estimation module; wherein, it includes: a first carrier NCO unit, configured to generate a local carrier based on a carrier frequency; a first mixer, coupled to the first carrier NCO unit, configured to receive the input signal and the local carrier output by the first carrier NCO and perform mixing; and a first spread spectrum code generation unit, configured to generate a random pseudo code sequence; a second correlation unit, coupled to the first spread spectrum code generation unit and the first mixer is coupled, configured to receive the local pseudo code output by the first spread spectrum code generating unit and the input signal stripped of the carrier output by the first mixer and perform correlation operation; a third coherent accumulation unit is coupled to the second correlation unit, configured to receive the output of the second correlation unit and perform coherent accumulation operation; a squaring unit is coupled to the third coherent accumulation unit, configured to receive the output of the third coherent accumulation unit and perform noise power estimation; and a smoothing filtering unit is coupled to the squaring unit, configured to filter the output of the squaring unit and obtain the noise power.

[0008] In particular, in the chip, when the narrowband energy statistical estimation value is invalid, the carrier-to-noise ratio calculation unit is configured to obtain a second carrier-to-noise ratio based on the broadband energy statistical estimation value and the noise power.

[0009] In particular, in the chip, when the narrowband energy statistical estimation value is valid, the carrier-to-noise ratio calculation unit is configured to obtain a third carrier-to-noise ratio based on the narrowband energy statistical estimation value and the noise power.

[0010] In particular, the chip, wherein the signal tracking channel also includes: a complex square unit, coupled to the first coherent accumulation unit, configured to receive the output of the first coherent accumulation unit and perform a complex square operation; and a multiplexing unit, coupled to the first correlation unit and the complex square unit, configured to receive the output of the complex square unit or the first correlation unit and output it to the second coherent accumulation unit.

[0011] In particular, the chip, wherein the signal tracking channel also includes: a second carrier NCO unit, configured to reproduce a local carrier based on a carrier frequency; a second mixer, coupled to the second carrier NCO unit, configured to receive the input signal and the local carrier output by the second carrier NCO unit and perform mixing to obtain an input signal stripped of the carrier; and a second spread spectrum code generating unit, configured to reproduce a pseudocode sequence based on a pseudocode phase; a third correlation unit, coupled to the second spread spectrum code generating unit and the second mixer, configured to receive the input signal stripped of the carrier and the pseudocode sequence and perform correlation operations to obtain an input signal stripped of the carrier and the pseudocode.

[0012] The present application also relates to a receiver for improving the carrier-to-noise ratio of a satellite signal, comprising a satellite signal processing chip as described above.

[0013] The present application also relates to a method for improving the carrier-to-noise ratio of a satellite signal, comprising: stripping a carrier and a pseudo code from an input signal; performing a coherent accumulation operation on the input signal stripped of the carrier and the pseudo code; performing a polarity decision on the result of the coherent accumulation operation; obtaining a narrowband energy statistical estimate based on the polarity decision result, and / or obtaining a broadband energy statistical estimate based on the result of the coherent accumulation operation.

[0014] In particular, the method described herein, wherein, when the signal-to-noise ratio is greater than or equal to 5 dB, a narrowband energy statistical estimation value is obtained based on the polarity decision result.

[0015] In particular, the method described herein is characterized in that a first carrier-to-noise ratio is obtained based on the statistical estimation value of the wideband energy and the statistical estimation value of the narrowband energy.

[0016] In particular, the method further includes obtaining the noise power of the input signal stripped of the carrier and the pseudo code.

[0017] In particular, the method described herein, wherein, when the narrowband energy statistical estimate value is invalid, a second carrier-to-noise ratio is obtained based on the wideband energy statistical estimate value and the noise power.

[0018] In particular, the chip, wherein, when the narrowband energy statistical estimation value is valid, a third carrier-to-noise ratio is obtained based on the narrowband energy statistical estimation value and the noise power.

[0019] The present application improves the performance of the carrier-to-noise ratio and carrier-to-noise ratio redundancy as well as the positioning and navigation capabilities of a GNSS receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Below, the preferred embodiments of the present application will be further described in detail with reference to the accompanying drawings, wherein:

[0021] Figure 1 FIG. 1 is a schematic diagram of the structure of a GNSS receiver according to an embodiment of the present application;

[0022] Figure 2 The figure is a schematic diagram of the structure of a satellite signal processing chip according to an embodiment of the present application;

[0023] Figure 3 FIG. 1 is a diagram showing a relationship between a bit error rate and a signal-to-noise ratio of an equal-probability binary bipolar signal according to an embodiment of the present application;

[0024] Figure 4 Shown is a schematic diagram of the structure of a satellite signal processing chip according to another embodiment of the present application. DETAILED DESCRIPTION

[0025] 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.

[0026] 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.

[0027] The technologies, methods and devices known to those skilled in the art may not be discussed in detail, but where appropriate, the technologies, methods and devices shall be considered as part of the specification. The lines between the units in the drawings are only for the convenience of explanation, indicating that at least the units at both ends of the lines are communicating with each other, and are not intended to limit the unconnected units from being 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 be able to communicate with each other through the signals shown in the figure.

[0028] The present application proposes a chip for improving the carrier-to-noise ratio of satellite signals, which can effectively improve the carrier-to-noise ratio reliability of GNSS receivers for satellite signals without pilot components and with high data transmission rates, improve the performance of wide- and narrow-band estimation of carrier-to-noise ratios and carrier-to-noise ratio estimation redundant information, and provide high-quality carrier-to-noise ratios and related redundant information for capture, tracking, positioning, speed measurement, and timing.

[0029] Figure 1 FIG. 4 is a schematic diagram of the structure of a GNSS receiver according to an embodiment of the present application.

[0030] 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 .

[0031] According to one embodiment, the antenna 11 is configured to receive radio frequency signals transmitted by a satellite.

[0032] 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.

[0033] 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.

[0034] 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, thereby reducing the amount of subsequent baseband signal operations by reducing the sampling frequency.

[0035] 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 the satellite signal, and obtain the pseudo code phase and carrier frequency. The carrier frequency may also include the Doppler frequency. In one embodiment, the output of the downsampling module 14 may include a digital intermediate frequency signal.

[0036] 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, and perform noise power estimation on the output of the downsampling module 14, so as to further enable the GNSS receiver to implement signal-to-noise ratio calculation and interference detection. 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.

[0037] According to one embodiment, the GNSS receiver further includes a signal tracking module 17 coupled to the downsampling module 14, the capture module 15, and the noise statistics module 16. The signal tracking channel 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, and the noise power of the corresponding frequency point output by the noise statistics module 16, and achieve synchronous locking of the satellite signal by precisely reproducing the local carrier and pseudo code, thereby achieving complete stripping of the satellite signal and stable output of observation quantities such as code phase, carrier phase, carrier-to-noise ratio, etc.

[0038] According to one embodiment, the GNSS receiver further includes a PVT solution module 18 coupled to the signal tracking channel 17. The PVT solution module 18 is configured to receive the observations output by the signal tracking channel 17, solve the observations and obtain the receiver position, velocity and time information.

[0039] According to one embodiment, a GNSS receiver includes a satellite signal processing chip. The satellite signal processing chip includes a carrier-to-noise ratio estimation module configured to calculate the carrier-to-noise ratio of the satellite signal. In one embodiment, the carrier-to-noise ratio estimation module may include a signal tracking channel to obtain the carrier-to-noise ratio based on wide-band and narrow-band power estimation. In another embodiment, the carrier-to-noise ratio estimation module may include a signal tracking channel and a noise statistics module, and the carrier-to-noise ratio estimation module obtains the carrier-to-noise ratio and the carrier-to-noise ratio redundant information based on the wide-band and narrow-band power estimation, thereby improving the ability to obtain the carrier-to-noise ratio redundant information.

[0040] Figure 2 Shown is a schematic diagram of the structure of a satellite signal processing chip according to an embodiment of the present application. Figure 2 The satellite signal processing chip shown includes a signal tracking channel 27 .

[0041] According to one embodiment, the signal tracking channel 27 includes a carrier NCO unit 2701 and a mixer 2702. The carrier NCO unit 2701 is configured to reproduce a local carrier based on a carrier frequency. The mixer 2702 is coupled to the carrier NCO unit 2701 and configured to receive an input signal and a local carrier output by the carrier NCO unit 2701, mix the local carrier with the input signal, synchronize and lock the input signal using the local carrier, and obtain and output an input signal stripped of the carrier. The input signal may be, for example, a digital intermediate frequency signal output by the downsampling module 14.

[0042] According to one embodiment, the signal tracking channel 27 includes a spread spectrum code generating unit 2703 and a correlation unit 2704. The spread spectrum code generating unit 2703 is configured to reproduce a local pseudo code based on a pseudo code phase. The correlation unit 2704 is coupled to the mixer 2702 and the spread spectrum code generating unit 2703, and is configured to receive an input signal stripped of a carrier output by the mixer 2702 and a local pseudo code output by the spread spectrum code generating unit 2703, perform a correlation operation on the local pseudo code and the input signal stripped of a carrier, and use the local pseudo code to perform synchronization locking on the input signal stripped of a carrier, thereby obtaining an input signal stripped of a carrier and a pseudo code.

[0043] According to one embodiment, the signal tracking channel 27 further includes a first-stage coherent accumulation unit 2705 coupled to the correlation unit 2704. The first-stage coherent accumulation unit 2705 is configured to receive a plurality of correlation operation results output by the correlation unit 2704, and perform coherent accumulation of the plurality of correlation operation results per unit time length, wherein the unit time length may be, for example, 1 ms, 2 ms, etc.

[0044] According to one embodiment of the present application, the first-stage coherent accumulation unit 2705 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 constant during the tracking of a satellite signal; 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 signal tracking channel 27 further includes a complex square unit 2706 coupled to the first-stage coherent accumulation unit 2705. The complex square unit 2706 is configured to receive the first-stage coherent accumulation result output by the first-stage coherent accumulation unit 2705, and perform a complex square operation on the first-stage coherent accumulation result. According to one embodiment, in the carrier-to-noise ratio estimation module, the signal tracking channel 27 may not include the complex square unit 2706.

[0048] According to one embodiment, the signal tracking channel 27 may further include a polarity decision unit 2707. The polarity decision unit 2707 may be coupled to the first-stage coherent accumulation unit 2705, and configured to receive the first-stage coherent accumulation result output by the first-stage coherent accumulation unit 2705, and perform polarity decision and obtain the polarity decision result based on the output of the first-stage coherent accumulation unit 2705. For different input signals, when the signal is strong, the phase of the input signal may be adjusted based on the polarity decision result to reduce the bit error rate and improve the tracking performance of the signal tracking channel.

[0049] According to one embodiment, the signal tracking channel 27 further includes a correlation unit 2708 coupled to the polarity decision unit 2707 and the first-stage coherent accumulation unit 2705. The correlation unit 2708 is configured to receive the first-stage coherent accumulation result output by the first-stage coherent accumulation unit 2705 and the polarity decision result output by the polarity decision unit 2707, and perform a correlation operation on the first-stage coherent accumulation result and the polarity decision result.

[0050] According to one embodiment, the signal tracking channel 27 further includes a multiplexing unit 2709 coupled to the complex square unit 2706 and the correlation unit 2708. The multiplexing unit 2709 is configured to output the complex square operation result output by the received complex square unit 2706 or the output of the correlation unit 2708. In the carrier-to-noise ratio estimation module, the output of the multiplexing unit 2709 is always the output of the correlation unit 2708.

[0051] According to one embodiment, the signal tracking channel 27 may further include a second-stage coherent accumulation unit 2710 configured to receive the output of the multiplexing unit 2709 and perform a coherent accumulation operation.

[0052] According to one embodiment, the signal tracking channel 27 includes a narrowband energy statistics unit 2712 coupled to the second-stage coherent accumulation unit 2710. The narrowband energy statistics unit 2712 is configured to receive the output of the second-stage coherent accumulation unit 2710 and perform statistical estimation. In one embodiment of the present application, the narrowband energy is calculated once every M second-stage coherent accumulations. , M is an integer greater than or equal to 1, the narrowband energy Can be modeled as

[0053] (2)

[0054] The narrowband energy statistics unit has a built-in smoothing filter operation to Perform statistical estimation to obtain the narrowband energy Statistical estimates of .

[0055] According to one embodiment, the signal tracking channel 27 may further include a broadband energy statistics unit 2711 coupled to the first-stage coherent accumulation unit 2705. The broadband energy statistics unit 2711 is configured to receive the output of the first-stage coherent accumulation unit 2705 and perform statistical estimation. In one embodiment of the present application, the broadband energy is calculated once for every M first-stage coherent accumulation results. , broadband energy Modeled as

[0056] (3)

[0057] in, is the first level coherent accumulation unit Sub-coherent accumulation result The broadband energy statistics module has a built-in smoothing filter operation to Perform statistical estimation to obtain broadband energy Statistical estimates of .

[0058] According to one embodiment of the present application, the carrier-to-noise ratio calculation unit 2713 is coupled to the broadband energy statistics unit 2711 and the narrowband energy statistics unit 2712. The carrier-to-noise ratio calculation unit 2713 is configured to receive the broadband energy statistics estimation value from the broadband energy statistics unit 2711. , and / or, the narrowband energy statistics estimate from the narrowband energy statistics unit 2712 When the broadband energy statistics estimate and narrowband energy statistics estimates When valid, calculate the carrier-to-noise ratio for

[0059] (4)

[0060] In one embodiment, when the signal tracking channel is an additive white Gaussian noise channel, the bit error rate of the first-stage coherent accumulation result output by the first-stage coherent accumulation unit in the signal tracking channel is SNR The relationships are

[0061] (5)

[0062] (6)

[0063] 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, The signal-to-noise ratio of the signal tracking channel is 0.00595387. When the bit error rate is greater than 5dB Less than 1%.

[0064] According to one embodiment, the polarity decision threshold is set to 5dB. When it is greater than or equal to 5dB, a polarity decision unit is used to perform polarity decision on the output of the first-stage coherent accumulation unit, and the narrowband energy statistical estimation value is obtained based on the result of the polarity decision.

[0065] In the prior art, for signals such as GEO B1I, although it is possible to The satellite signal processing chip proposed in this application obtains a narrowband energy statistical estimate with better performance based on the output of the polarity decision unit when the signal-to-noise ratio of the satellite signal is greater than or equal to 5dB, which helps to improve the performance of the carrier-to-noise ratio obtained based on the wide-band and narrow-band power estimation, and can effectively improve the reliability of the carrier-to-noise ratio estimation of the GNSS receiver for satellite signals with higher data transmission rates. In particular, a narrowband energy statistical estimate with higher performance is obtained based on the polarity decision result. , which can significantly improve the narrowband energy statistical performance of satellite signals such as B2b and GEO B1I.

[0066] Figure 4 Shown is a schematic diagram of the structure of a satellite signal processing chip according to another embodiment of the present application. Figure 4 The satellite signal processing chip shown includes a noise statistics module 46 and a signal tracking channel 47. The signal tracking channel 47 can be connected to Figure 2 The signal tracking channels shown have a similar structure.

[0067] According to one embodiment, the noise estimation module 46 has the same noise statistics as the signal tracking channel.

[0068] According to one embodiment, the noise statistics module 46 includes a carrier NCO unit 4601 and a mixer 4602. The carrier NCO unit 4601 is configured to reproduce a local carrier based on a carrier frequency. The mixer 4602 is coupled to the carrier NCO unit 4601 and configured to receive an input signal and a local carrier and perform mixing.

[0069] According to one embodiment, the noise statistics module 46 further includes a spread spectrum code generation unit 4603 and a correlation unit 4604. The spread spectrum code generation unit 4603 is configured to generate a pseudo code sequence based on a randomly selected pseudo code initial phase, and the pseudo code sequence may include a pseudo code sequence at the same frequency point as the input signal or a random pseudo code sequence. The correlation unit 4604 is coupled to the mixer 4602 and the spread spectrum code generation unit 4603, and is configured to receive the output of the mixer 4602 and the pseudo code sequence output by the spread spectrum code generation unit 4603, and perform a correlation operation.

[0070] According to one embodiment, the noise statistics module 46 further includes a coherent accumulation unit 4605. The coherent accumulation unit 4605 is coupled to the correlation unit 4604, and is configured to receive a plurality of correlation operation results output by the correlation unit 4604, and perform coherent accumulation of the plurality of correlation operation results per unit time length, wherein the unit time length may be, for example, 1 ms, 2 ms, etc.

[0071] According to one embodiment, the noise statistics module 46 may further include a square unit 4606. The square unit 4606 is coupled to the coherent accumulation unit 4605 and is configured to receive the coherent accumulation result output by the coherent accumulation unit 4605 and perform noise power estimation.

[0072] According to one embodiment, the noise statistics module 46 further includes a smoothing filter unit 4615. The smoothing filter unit 4615 is coupled to the square unit 4606 and is configured to receive the noise power estimate output by the square unit 4606, perform smoothing filtering on the noise power estimate and output the statistical noise power. .

[0073] According to one embodiment, the signal tracking channel 47 includes a broadband energy statistics unit 4711, a narrowband energy statistics unit 4712 and a carrier-to-noise ratio calculation unit 4713. The carrier-to-noise ratio calculation unit 4713 is coupled to the broadband energy statistics unit 4711, the narrowband energy statistics unit 4712 and the noise estimation channel 46. The carrier-to-noise ratio calculation unit 4713 is configured to receive the broadband energy statistics estimation value from the broadband energy statistics unit 4711. , the narrowband energy statistics estimate from the narrowband energy statistics unit 4712 , and the noise power from the noise statistics module 46 , and based on broadband energy statistics estimates and noise power Obtaining broadband carrier-to-noise ratio , and / or, based on narrowband energy statistical estimates Sum and noise power Obtaining narrowband carrier-to-noise ratio .

[0074] In one embodiment of the present application, when the narrowband energy statistical estimate When invalid, obtain a broadband carrier-to-noise ratio based on the broadband energy statistical estimate and the noise power .

[0075] (7)

[0076] In another embodiment of the present application, when the narrowband energy statistical estimate When valid, the narrowband carrier-to-noise ratio is obtained based on the narrowband energy statistical estimate and the noise power .

[0077] (8)

[0078] Obtain narrowband energy statistical estimate based on polarity decision results , and then obtain the narrowband carrier-to-noise ratio , which helps to improve the carrier-to-noise ratio redundant information of the carrier-to-noise ratio estimation module based on the signal-to-noise ratio and enhance the service quality of the GNSS receiver.

[0079] The present application also includes a satellite signal carrier-to-noise ratio estimation method. According to an embodiment of the present application, the method can be executed by a satellite signal processing chip.

[0080] Step 501: strip the carrier and pseudo code from the input signal.

[0081] Step 502: Obtain the noise power of the input signal stripped of the carrier and the pseudo code .

[0082] Step 503: perform a coherent accumulation operation on the input signal stripped of the carrier and the pseudo code.

[0083] Step 504: performing polarity determination on the coherent accumulation operation result.

[0084] According to one embodiment, when the signal-to-noise ratio is greater than or equal to 5 dB, a correlation operation is performed on the polarity decision result and the coherent accumulation operation result.

[0085] Step 505: Obtain a narrowband energy statistical estimate based on the result of the polarity judgment , and , based on the coherent accumulation operation results, obtain the broadband energy statistical estimate .

[0086] Step 506: When the narrowband energy statistical estimation value and the broadband energy statistical estimation value are valid, based on the broadband energy statistical estimation value and narrowband energy statistics estimates Get the carrier-to-noise ratio .

[0087] Step 507: when the narrowband energy statistical estimation value is invalid, based on the broadband energy statistical estimation value and noise power Obtaining broadband carrier-to-noise ratio When the narrowband energy statistical estimate is valid, the and noise power Obtaining narrowband carrier-to-noise ratio .

[0088] According to one embodiment, when the signal type is B2b, GEO B1I, etc. and the signal-to-noise ratio is greater than or equal to 5dB, a polarity decision is performed on the coherent accumulation operation result, and a narrowband energy statistical estimate is obtained based on the result of the polarity decision. And obtain broadband energy statistics estimation based on the coherent accumulation operation results At this time, based on the broadband energy statistics estimation Obtaining broadband carrier-to-noise ratio , and based on narrowband energy statistics estimation Get narrowband carrier-to-noise ratio .

[0089] The satellite signal processing chip proposed in the present application obtains a narrowband carrier-to-noise ratio with better performance based on the output of the polarity judgment unit, which helps to improve the performance of the carrier-to-noise ratio obtained based on wide-band and narrow-band power estimation, improves the reliability of the carrier-to-noise ratio and the carrier-to-noise ratio redundant information, and enables the GNSS receiver to obtain high-quality observations from more satellite signals, thereby improving the receiver's positioning and navigation capabilities.

[0090] The present application also provides a receiver for improving the carrier-to-noise ratio of a satellite signal, comprising any of the satellite signal processing chips described above.

[0091] 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 to improve the carrier-to-noise ratio of satellite signals, including a carrier-to-noise ratio estimation module, which includes a signal tracking channel; The signal tracking channel includes: A first coherent accumulation unit is configured to receive an input signal stripped of a carrier and a pseudo code and perform a coherent accumulation operation on the input signal; a polarity decision unit, coupled to the first coherent accumulation unit, configured to receive the output of the first coherent accumulation unit and perform polarity decision; A first correlation unit, coupled to the first coherent accumulation unit and the polarity decision unit, configured to receive outputs of the first coherent accumulation unit and the polarity decision unit and perform a correlation operation on the two; A second coherent accumulation unit, configured to perform a coherent accumulation operation based on the output of the polarity decision unit; A broadband energy statistics unit, coupled to the first coherent accumulation unit, configured to perform statistical estimation on an output from the first coherent accumulation unit to obtain a broadband energy statistics estimation value; a narrowband energy statistics unit, coupled to the second coherent accumulation unit, configured to perform statistical estimation on an output from the second coherent accumulation unit to obtain a narrowband energy statistics estimation value; The carrier-to-noise ratio calculation unit is coupled to the broadband energy statistics unit and the narrowband energy statistics unit, and is configured to receive the broadband energy statistics estimation value and / or the narrowband energy statistics estimation value.

2. The chip according to claim 1, wherein: When the signal-to-noise ratio is greater than or equal to 5 dB, the narrowband energy statistics unit is configured to obtain the narrowband energy statistics estimation value based on the polarity decision result of the polarity decision unit.

3. The chip according to claim 2, wherein: The carrier-to-noise ratio calculation unit is configured to obtain a first carrier-to-noise ratio based on the wideband energy statistical estimation value and the narrowband energy statistical estimation value.

4. The chip according to claim 2, further comprising A noise estimation channel is configured to perform noise power estimation on the input signal and obtain noise power, and output the noise power to the carrier-to-noise ratio calculation unit of the carrier-to-noise ratio estimation module; wherein, include: A first carrier NCO unit configured to generate a local carrier based on a carrier frequency; A first mixer, coupled to the first carrier NCO unit, configured to receive the input signal and a local carrier output by the first carrier NCO and perform mixing; as well as, A first spread spectrum code generating unit configured to generate a random pseudo code sequence; a second correlation unit, coupled to the first spread spectrum code generating unit and the first mixer, configured to receive the local pseudo code output by the first spread spectrum code generating unit and the input signal stripped of the carrier output by the first mixer and perform a correlation operation; a third coherent accumulation unit, coupled to the second correlation unit, configured to receive the output of the second correlation unit and perform a coherent accumulation operation; a square unit, coupled to the third coherent accumulation unit, configured to receive the output of the third coherent accumulation unit and perform noise power estimation; as well as The smoothing filter unit is coupled to the square unit and is configured to filter the output of the square unit and obtain the noise power.

5. The chip according to claim 4, wherein: When the narrowband energy statistical estimation value is invalid, the carrier-to-noise ratio calculation unit is configured to obtain a second carrier-to-noise ratio based on the wideband energy statistical estimation value and the noise power.

6. The chip according to claim 4, wherein: When the narrowband energy statistical estimation value is valid, the carrier-to-noise ratio calculation unit is configured to obtain a third carrier-to-noise ratio based on the narrowband energy statistical estimation value and the noise power.

7. The chip according to claim 1, wherein: The signal tracking channel also includes: a complex square unit, coupled to the first coherent accumulation unit, configured to receive an output of the first coherent accumulation unit and perform a complex square operation; and A multiplexing unit is coupled to the first correlation unit and the complex square unit, and is configured to output the received output of the complex square unit or the first correlation unit to the second coherent accumulation unit.

8. The chip according to claim 7, wherein: The signal tracking channel also includes: a second carrier NCO unit configured to reproduce a local carrier based on the carrier frequency; A second mixer, coupled to the second carrier NCO unit, is configured to receive the input signal and the local carrier output by the second carrier NCO unit and perform mixing to obtain an input signal stripped of the carrier; and A second spread spectrum code generating unit is configured to reproduce a pseudo code sequence based on a pseudo code phase; The third correlation unit is coupled to the second spread spectrum code generating unit and the second mixer, and is configured to receive the input signal stripped of the carrier and the pseudo code sequence and perform correlation operations to obtain the input signal stripped of the carrier and the pseudo code.

9. A receiver for improving the carrier-to-noise ratio of a satellite signal, comprising the chip for improving the carrier-to-noise ratio of a satellite signal as claimed in any one of claims 1 to 8.

10. A method for improving satellite signal carrier-to-noise ratio using the chip for improving satellite signal carrier-to-noise ratio according to any one of claims 1 to 8, comprising: Strip the carrier and pseudo code of the input signal; Performing a coherent accumulation operation on the input signal stripped of the carrier and the pseudo code; Performing polarity judgment on the coherent accumulation operation result; A narrowband energy statistical estimation value is obtained based on the polarity decision result, and / or a wideband energy statistical estimation value is obtained based on the result of the coherent accumulation operation.

11. The method according to claim 10, wherein: When the signal-to-noise ratio is greater than or equal to 5 dB, a narrowband energy statistical estimation value is obtained based on the polarity decision result.

12. The method according to claim 11, wherein: A first carrier-to-noise ratio is obtained based on the statistical estimation value of the wideband energy and the statistical estimation value of the narrowband energy.

13. The method according to claim 11, further comprising, The noise power of the input signal stripped of the carrier and the pseudo code is obtained.

14. The method according to claim 13, wherein: When the narrowband energy statistical estimation value is invalid, a second carrier-to-noise ratio is obtained based on the wideband energy statistical estimation value and the noise power.

15. The method according to claim 13, wherein: When the narrowband energy statistical estimation value is valid, a third carrier-to-noise ratio is obtained based on the narrowband energy statistical estimation value and the noise power.

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