A low power consumption control method for GNSS receiver
By dynamically adjusting the working status of the capture module and RF front-end of the GNSS receiver, adjusting the control strategy and RF gain of the capture module according to the environment, the problem of high power consumption of the GNSS receiver in complex environments is solved, and the GNSS receiver is realized in different environments balance of positioning quality and power consumption.
Patent Information
- Application Number
- CN202210864962.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-07-21
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-07-21
AI Technical Summary
GNSS receivers consume high power when tracking multiple satellite signals and frequency bands, resulting in short battery life and it is difficult for the prior art to balance positioning performance and power consumption requirements in complex environments.
By counting the number of tracking channels and the number of strong stars, dynamically adjust the working status of the capture module and the RF front-end, step-by-step control of the capture module switch cycle and RF gain gear, adjust the control strategy of the capture module and the function of the RF front-end according to the environment. Consumption.
Timely capture new satellites in different environments, ensuring positioning quality while reducing power consumption, and balancing the performance and power consumption of the receiver.
Smart Images
Figure CN115308782B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of satellite positioning technology, and in particular to a low power consumption control method for a GNSS receiver. Background Art
[0002] With the increasing application of IoT technology and the use of wearable devices based on location-based services (LBS), the market demand for GNSS receiver chips continues to grow. However, due to the limitation of device size, the battery must be small, and in the process of using GNSS positioning function, the capture and tracking of satellite signals and positioning services usually consume a lot of power, resulting in a short battery life, which challenges the mass consumer market's requirements for GNSS low power consumption. In order to ensure normal and continuous positioning in complex and changing environments, software is required to balance positioning performance and power consumption requirements in the best way.
[0003] Current GNSS receivers provide a variety of methods to balance the conflicting needs between positioning availability and accuracy and power consumption. Tracking multiple GNSS constellations and frequency bands simultaneously increases the number of visible satellites, thereby improving the robustness of positioning; in environments with poor signals, such as in urban canyons or under the shade of trees, multi-frequency and multi-constellation can significantly improve the availability, accuracy and reliability of positioning services. However, in terms of power consumption, tracking more GNSS constellations and frequency bands causes the receiver to spend more time capturing satellite signals, thereby increasing power consumption. In addition, when tracking GNSS signals in different frequency bands, the receiver requires additional RF circuits to pre-process the signals, which also increases power consumption. At the same time, the RF front end requires more power consumption to improve weak signal gain.
[0004] The application's GNSS performance requirements will limit the options available for reducing power consumption. Developers need to carefully consider performance and power consumption choices to fully meet the needs of the target application. The general solution controls the capture module switch based on the positioning situation. However, the traditional method has a single control item, which only controls the capture module switch based on the number of tracked satellites. Therefore, it can only meet the performance requirements of specific use cases. When there is an occlusion or attenuation environment, it cannot capture new satellites in time, thus affecting the positioning quality. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a low power consumption control method for a GNSS receiver, which can balance performance and minimum power consumption.
[0006] The technical solution adopted by the present invention to solve the technical problem is: to provide a GNSS receiver low power consumption control method, comprising the following steps:
[0007] Turning on the GNSS receiver to complete the initial positioning, during which the RF front end of the GNSS receiver maintains a first gain gear and the capture module of the GNSS receiver remains in an open state;
[0008] Counting the number of occupied tracking channels of the tracking module, and obtaining the number of tracked strong satellites according to the number of occupied tracking channels;
[0009] Determining the control strategy of the capture module according to the number of tracked strong stars;
[0010] Determining the gain level of the radio frequency front end according to the number of tracked strong satellites;
[0011] According to the determined control strategy of the capture module and the gain level of the RF front end, the working state of the capture module and the RF front end are adjusted to achieve power consumption adjustment.
[0012] The number of occupied tracking channels of the statistical tracking module and the number of tracked strong satellites obtained according to the number of occupied tracking channels are specifically:
[0013] Counting the number of occupied tracking channels of the tracking module of the GNSS receiver;
[0014] According to the set strong star threshold, the number of tracking channels exceeding the strong star threshold is counted from the tracking channels, and the number is the number of tracked strong stars.
[0015] The strong satellite threshold is set according to the antenna OTA performance.
[0016] The control strategy for determining the capture module according to the number of tracked strong stars is specifically:
[0017] Determine the current positioning situation according to the number of tracked strong satellites, wherein the current positioning situation includes an open sky environment, a half-sky blocked environment, and a weak signal environment;
[0018] When the current positioning situation is an open sky environment, the control strategy of the capture module is: controlling the first closing time of the capture module according to the number of tracked strong satellites, and reopening the capture module after the first closing time to perform a round of satellite capture, and the capture module repeatedly works at the first working frequency;
[0019] When the current positioning situation is a half-sky obstruction environment, the control strategy of the capture module is: control the capture module to close the capture module after completing multiple rounds of capture, and reopen the capture module to capture satellites after a second closing time, and the capture module repeats the work at the second working frequency;
[0020] When the current positioning situation is a weak signal environment, the control strategy of the capture module is: controlling the capture module to be in a normally open state, and the capture module operates at a second operating frequency;
[0021] The first operating frequency is lower than the second operating frequency.
[0022] The round of satellite capture refers to a satellite being captured in a mode from a capture mode with a short integration time to a capture mode with a long integration time.
[0023] Determining the current positioning situation according to the number of tracked strong stars is specifically as follows:
[0024] When the number of tracked strong satellites is greater than or equal to N2, the current positioning situation is an open sky environment;
[0025] When the number of tracked strong satellites is greater than or equal to N3 and less than N2, the current positioning situation is a half-sky obstruction environment;
[0026] When the number of tracked strong satellites does not exceed N4, the current positioning situation is a weak signal environment;
[0027] Among them, N4 <N3<N2。
[0028] When the current positioning situation is an open sky environment, if the number of tracked strong stars is greater than or equal to N1, the first closing time is T1off seconds, and the opening time of the capture module for a round of satellite capture is T1on seconds; otherwise, the first closing time is T2off seconds, and the opening time of the capture module for a round of satellite capture is T2on seconds, where T1off seconds is the time when the capture module is closed. <T2off,T1on<T2on,N1> N2.
[0029] When determining the control strategy of the capture module according to the number of tracked strong satellites, it is also determined whether it is a single-mode usage scenario. If so, the satellite number threshold Ni is set. When the number of tracked strong satellites is greater than or equal to the satellite number threshold Ni, the control strategy of the capture module is: turn off the capture module for T4off seconds, and then reopen the capture module, and the capture module operates at the second operating frequency.
[0030] The step of determining the gain level of the RF front end according to the number of tracked strong stars is specifically as follows:
[0031] Determine the current positioning situation according to the number of tracked strong satellites, wherein the current positioning situation includes an open sky environment, a half-sky blocked environment, and a weak signal environment;
[0032] When the current positioning situation is an open sky environment, the RF front end is set to the second gain level;
[0033] When the positioning situation is a half-sky blocking environment or a weak signal environment, the RF front end is set to the first gain gear;
[0034] The gain of the first gain level is higher than the gain of the second gain level.
[0035] Beneficial Effects
[0036] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: the present invention sets the strong satellite tracking threshold according to the antenna OTA performance, and counts the number of strong satellites tracked based on the strong satellite tracking threshold, and dynamically adjusts the RF gain and the control strategy of the capture module according to the current number of strong satellites tracked, so that new satellites can be captured in time under different environments, while ensuring the positioning quality and reducing power consumption, thereby balancing the performance and power consumption of the receiver. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 is a framework diagram of a GNSS receiver in an embodiment of the present invention;
[0038] Figure 2 It is a schematic diagram of capturing the switching cycle and power consumption changes of the module;
[0039] Figure 3 It is a flow chart of a low power consumption control method for a GNSS receiver according to an embodiment of the present invention. DETAILED DESCRIPTION
[0040] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.
[0041] like Figure 1 As shown, the GNSS receiver includes an antenna, an RF front end, a baseband hardware module, and an MCU processor.
[0042] For dual-frequency receivers, the RF front end requires multiple hardware paths to pre-process other frequency signals such as L1 and L5, and convert analog signals into digital intermediate frequency signals. According to the sensitivity design requirements, the RF path needs to meet a certain gain amount. The larger the gain, the greater the current consumption. For LNAs with internal gain settings, the RF path gain can be adjusted according to environmental conditions to reduce the power consumption required to achieve GNSS sensitivity and accuracy.
[0043] The baseband module converts the digital intermediate frequency signal into a baseband signal for capture and tracking. The baseband module mainly includes the capture module (AE) and the tracking module (TE), which are responsible for GNSS signal capture and tracking. AE is an intermittent working mode, which is enabled after startup or when the number of satellites does not meet the positioning requirements. It can be turned off to reduce power consumption after the positioning requirements are met. TE is a continuous working mode, which needs to track satellite signals and report the observed values. The ephemeris data update and position solution are completed in the solution module in the MCU. Unless the satellite is invisible or loses its position or the environment changes drastically, the receiver will maintain the satellite continuous tracking mode. It is necessary to adjust the AE switching strategy and the number of TE tracking channels to balance positioning performance and power consumption.
[0044] The MCU processor unit controls the start and stop of the GNSS function, performs AE acquisition control, TE tracking loop control, observation extraction and processing, satellite message decoding, positioning solution, and interface control, etc. The MCU adjusts the power consumption strategy and controls the enabling of related modules according to the positioning performance and power consumption requirements.
[0045] The power consumption difference between RF gain levels is basically fixed. Adjust the RF gain level according to the positioning situation and signal strength.
[0046] like Figure 2 As shown in the figure, after the AE module is turned on, the power consumption increases by about 20%-25%. The AE capture module continues to run, which keeps the power consumption at a high level. It is necessary to control the AE switching cycle according to the positioning situation and the number of TE tracking satellites to reduce the average power consumption.
[0047] After TE is running, the power consumption increase value is basically fixed for each additional channel. Controlling the number of TE channels according to the positioning situation affects the power consumption of the receiver. Performance and power consumption are contradictory and cannot be optimized at the same time. It is necessary to balance positioning performance and power consumption requirements.
[0048] The embodiment of the present invention relates to a GNSS receiver low power consumption control method, which controls power consumption options based on the number of tracked strong satellites. The number of tracked strong satellites determines the positioning accuracy. Based on performance priority, the method dynamically adjusts a series of settings such as RF gain, AE on and off, AE switch duration, AE operating frequency, and TE tracking channel number according to the current number of tracked strong satellites while ensuring positioning performance. It comprehensively controls from the RF front end to the software processing flow to balance performance and minimum power consumption. Figure 3 As shown, the specific steps include:
[0049] In step S01, the GNSS receiver starts to start, enters the initialization phase, sets the RF front end, and defaults to high gain position, and AE starts satellite acquisition. After AE successfully captures and switches to TE tracking, loop control and observation quantity extraction and reporting are completed in the TE tracking channel. Before completing the first positioning (TTFF), the RF front end maintains a high gain position and the AE remains turned on to capture as many high-energy satellites as possible and participate in positioning to ensure positioning accuracy. This stage is generally the peak power consumption stage.
[0050] In step S02, the number of TE tracking channel occupation and the number of tracked strong satellites are counted. For dual-frequency systems, due to the existence of TE multi-channel tracking, the actual number of TE tracking channels occupied is greater than the number of satellites. Therefore, the number of tracked strong satellites can be obtained based on the number of TE tracking channels occupied. According to the set strong star CN0 threshold X1, the number of tracking channels that exceed the strong star CN0 threshold X1 is counted, and this number is the number of tracked strong satellites. For dual-frequency systems, the L5 energy is not lower than L1. Here, it is only necessary to count the number of satellites whose L1 exceeds the strong star CN0 threshold X1. Among them, the setting of the strong star CN0 threshold X1 is determined according to the antenna OTA performance. For example, in the active antenna solution, the signal energy is high, and the strong star CN0 threshold X1 can be set to 33dBm.Hz. For the passive antenna solution, the signal energy is average, and the strong star CN0 threshold X1 can be lowered by 3-5dB.
[0051] Step S03 is the core part of this strong satellite strategy. In this step, the positioning situation is determined according to the number of strong satellites, and then the AE switch is controlled in a step-by-step and periodic manner. If there are many strong satellites to track, there are many satellites available for positioning, and the positioning accuracy is high, then the AE switch cycle is long to reduce power consumption. Otherwise, a short cycle switch AE is used to apply to the open sky environment, the half sky blocked environment, the weak signal environment blocked by the tree-lined avenue, etc.
[0052] The threshold of the number of strong stars in each scene and the AE switching cycle are adjusted and set after long-term testing based on the positioning performance of each typical scene under different signal energy intensities. When the number of strong stars is greater than or equal to N2, the current positioning situation is an open sky environment; when the number of strong stars is greater than or equal to N3 and less than N2, the current positioning situation is a half-sky blocked environment; when the number of strong stars is less than or equal to N4, the current positioning situation is a weak signal environment.
[0053] The AE strong star control strategy is shown in Table 1:
[0054] Table 1 Strong star low power consumption control strategy
[0055] Number of strong stars AEON / S AEOFF / S AEFREQ / MHz RFGAIN Not located —— Normally Open —— H H Open Sky 1 >＝N1 T1on T1off L L Open Sky 2 [N2~N1) T2on T2off L L Half the Sky Environment [N3~N2) T3on T3off H H Weak signal environment <＝N4 Normally Open —— H H Single mode >=Ni T4on T4off H H
[0056] For open sky scenarios, according to long-term stability operation analysis, the full-mode dual-frequency system, under normal antenna OTA performance, can track no less than 35-40 strong satellites. In this scenario, the AE switching cycle is relatively long. According to the number of strong satellites, AE is turned off for T1off or T2off seconds and then turned on again to capture satellites to cope with the changes in the elevation angle of some satellites that affect the visibility of satellites. The AE capture time is related to the current number of strong satellites. If there are many strong stars at present (>=N1), AE is turned off after completing a round of capture, which takes T1on seconds; if the number of strong stars is [N2~N1), AE is controlled to complete a round of high-sensitivity capture, which takes T2on seconds. When there are many strong stars, AE can run at a low frequency to further reduce power consumption.
[0057] In half-sky environments such as urban canyons and under elevated roads, signal reception is limited by the direction of obstruction, and the number of satellites that can be tracked is halved or less. In this scenario, AE needs to be turned on and off in a short period to capture visible satellites caused by changes in the receiver's position in a timely manner. At this time, the number of strong satellites is [N3~N2). After AE runs for T3on seconds to complete multiple rounds of capture, it is turned off. After turning off AE for T3off seconds, it is turned on again to capture satellites. In this signal environment, multiple rounds of high-sensitivity satellite capture are required, and the AE operating frequency is switched to high-frequency mode.
[0058] In obstructed environments such as tree-lined avenues, the signal strength is low and the strong satellites change dramatically. The number of strong satellites is small (<=N4), and the probability of satellite tracking loop losing lock is high. AE needs to be always on. After weak signals or receiver loss of positioning, AE switches to high-frequency working state to quickly complete satellite capture and repositioning.
[0059] For single-mode usage scenarios, set the satellite number threshold Ni according to the number of visible satellites in each system. If the number of tracked satellites is greater than or equal to Ni, turn off AE T4off seconds, then turn on AE again and complete several rounds of capture based on the current positioning situation and the number of tracked satellites.
[0060] After AE is turned on again, for the untracked visible stars, after completing a full round of search, AE will be controlled to continue capturing or turned off according to the current number of strong stars. When AE is turned off, if the environment changes or the strong stars change dramatically, AE should be turned on in time to quickly respond to the change in positioning status.
[0061] The above round of acquisition refers to a satellite switching from a fast acquisition mode with low sensitivity and short integration time to a high sensitivity acquisition mode with long integration time.
[0062] In step S04, the RF gain level is adjusted according to the positioning situation and the number of strong satellites. When the signal environment is good and the number of strong satellites is large (>=N2), the RF front-end gain can be adjusted to a low level to reduce the front-end power consumption. When the positioning is lost or the signal is weak, the RF is adjusted to a high gain level in time. Due to the existence of the front-end AGC circuit, even if the high and low gain levels are adjusted, the impact on the strong satellites is about 1dB, but the power consumption is significantly affected.
[0063] In step S05, according to the strong star strategy adjustment result, the RF front end and AE and other related hardware registers are configured to achieve power consumption adjustment.
[0064] Steps S02 to S05 are called periodically to count the number of tracking channels and strong satellites, adjust the AE switching cycle and RF gain, and fully implement the positioning performance and power consumption strategy adjustment.
[0065] It is not difficult to find that the present invention sets the strong satellite tracking threshold according to the antenna OTA performance, and counts the number of strong satellites tracked based on the strong satellite tracking threshold, and dynamically adjusts the RF gain and the control strategy of the capture module according to the current number of strong satellites tracked, so that new satellites can be captured in time in different environments, while ensuring the positioning quality and reducing power consumption, thereby balancing the performance and power consumption of the receiver.
Claims
1. A GNSS receiver low power consumption control method, characterized in that: The following steps are involved: Turning on the GNSS receiver to complete the initial positioning, during which the RF front end of the GNSS receiver maintains a first gain gear and the capture module of the GNSS receiver remains in an open state; Counting the number of occupied tracking channels of the tracking module, and obtaining the number of tracked strong satellites according to the number of occupied tracking channels; The control strategy of the capture module is determined according to the number of tracked strong stars, specifically: Determine the current positioning situation according to the number of tracked strong satellites, wherein the current positioning situation includes an open sky environment, a half-sky blocked environment, and a weak signal environment; When the current positioning situation is an open sky environment, the control strategy of the capture module is: controlling the first closing time of the capture module according to the number of tracked strong satellites, and reopening the capture module after the first closing time to perform a round of satellite capture, and the capture module repeatedly works at the first working frequency; When the current positioning situation is a half-sky obstruction environment, the control strategy of the capture module is: control the capture module to close the capture module after completing multiple rounds of capture, and reopen the capture module to capture satellites after a second closing time, and the capture module repeats the work at the second working frequency; When the current positioning situation is a weak signal environment, the control strategy of the capture module is: controlling the capture module to be in a normally open state, and the capture module operates at a second operating frequency; Wherein, the first operating frequency is lower than the second operating frequency; The current positioning situation is determined according to the number of tracked strong stars, specifically: When the number of tracked strong satellites is greater than or equal to N2, the current positioning situation is an open sky environment; When the number of tracked strong satellites is greater than or equal to N3 and less than N2, the current positioning situation is a half-sky obstruction environment; When the number of tracked strong satellites does not exceed N4, the current positioning situation is a weak signal environment; Among them, N4 <N3<N2; When the current positioning situation is an open sky environment, if the number of tracked strong stars is greater than or equal to N1, the first closing time is T1off seconds, and the opening time of the capture module for a round of satellite capture is T1on seconds; otherwise, the first closing time is T2off seconds, and the opening time of the capture module for a round of satellite capture is T2on seconds, where, T1off <T2off,T1on<T2on,N1> N2; Determining the gain level of the radio frequency front end according to the number of tracked strong satellites; The working states of the capture module and the radio frequency front end are adjusted according to the determined control strategy of the capture module and the gain gear of the radio frequency front end to achieve power consumption adjustment.
2. The GNSS receiver low power consumption control method according to claim 1, characterized in that: The number of occupied tracking channels of the statistical tracking module and the number of tracked strong satellites obtained according to the number of occupied tracking channels are specifically: Counting the number of occupied tracking channels of the tracking module of the GNSS receiver; According to the set strong star threshold, the number of tracking channels exceeding the strong star threshold is counted from the tracking channels, and the number is the number of tracked strong stars.
3. The GNSS receiver low power consumption control method according to claim 2, characterized in that: The strong satellite threshold is set according to the antenna OTA performance.
4. The GNSS receiver low power consumption control method according to claim 1, characterized in that: The round of satellite capture refers to a satellite being captured in a mode from a capture mode with a short integration time to a capture mode with a long integration time.
5. The GNSS receiver low power consumption control method according to claim 1, characterized in that: When determining the control strategy of the capture module according to the number of tracked strong satellites, it is also determined whether it is a single-mode usage scenario. If so, the satellite number threshold Ni is set. When the number of tracked strong satellites is greater than or equal to the satellite number threshold Ni, the control strategy of the capture module is: turn off the capture module for T4off seconds, and then reopen the capture module, and the capture module operates at the second operating frequency.
6. The GNSS receiver low power consumption control method according to claim 1, characterized in that: The step of determining the gain level of the RF front end according to the number of tracked strong stars is specifically as follows: Determine the current positioning situation according to the number of tracked strong satellites, wherein the current positioning situation includes an open sky environment, a half-sky blocked environment, and a weak signal environment; When the current positioning situation is an open sky environment, the RF front end is set to the second gain level; When the positioning situation is a half-sky blocking environment or a weak signal environment, the RF front end is set to the first gain gear; The gain of the first gain level is higher than the gain of the second gain level.