Xiaomi 8 is the world’s first dual-band GPS mobile phone that can achieve ultra-precise positioning. It can help all applications that require location services to improve the user experience. The conference mentioned that dual-frequency GPS can improve the positioning accuracy by 3-5 compared to traditional single-frequency GPS mobile phones. Times. So what's the actual effect?
This time, we have selected four high-frequency scenes that require the use of positioning services to be measured, including cell phones, micro-channels, real-time sharing, walking navigation, driving navigation, and adding two single-frequency GPS flagship mobile phones as reference.
Scenario 1: Comparison of car location
The furthest distance in the world is that you cannot find a driver when you are called a car. The driver can't find you. The inaccurate positioning often leads you to such an embarrassment that Lunan drivers are on Lubei. And this happens because Single-frequency GPS signals are caused by architectural obstructions and glass reflections in building-intensive areas. To demonstrate the performance of dual-frequency GPS in complex environments, we have also selected test sites in the China World Trade Center (CBD) with many high-rise buildings and many glass curtain walls.
Three testers stood at the same location on the A exit of the Guomao Subway Station. The three mobile phones simultaneously opened the same car calling software for positioning. The iPhone X and the Samsung S9 both showed certain deviations. The iPhone X shifted to the nearby China World Mall. The Samsung S9 simply drifted to the Yintai Center in the south. Only the Xiaomi 8 can be accurately positioned to the actual location.
Scenario 2: Comparison of real-time location of WeChat sharing
When he does not know exactly where he is and when you are looking for him again, WeChat share real-time location is a good solution. Of course, the premise of all this is positioning is accurate enough. Our three testers stood Jianwai SOHO in front of the same location, open the WeChat share location at the same time.
As a result, only the millet 8 is accurately positioned to the correct position, the iPhone X has a slight deviation, and the Samsung S9 has once again experienced a large positional shift.
Scenario 3: Comparison of walking navigation
To go to a nearby restaurant in a strange city, it is often necessary to use walking navigation. Three testers also set off from Jianwai SOHO and walked to the nearby Jinzhou Bank to test whether the navigation guidance of the three mobile phones is accurate. At the same starting point, use The same map software, three mobile phones give the same planning route.
In the process of walking navigation, Samsung S9 and iPhone X also showed a clear positioning drift, the tester could not accurately obtain their true position, the navigation direction was wrong, and the actual walking trajectory deviated from the planned route. The millet 8 was the shortest, almost No "due" phenomenon due to positioning offset.
As shown in the figure below, iPhone X and Samsung S9 have obvious 'wrap around' phenomenon, and even appear to pass through the building. Actually, this is not the actual travel route, but is due to the positioning offset. The route trajectory is a road map composed of positioning points for each positioning of the mobile phone during the course of travel. The more 'routes' appearing, the more errors in locating offsets appear in the process of walking navigation.
Scenario 4: Comparison of re-planning speeds of yaw route
When navigating in the car, there are often cases where we have already opened the intersection and the navigation prompts. We will put three mobile phones in the same car and test it on the Beijing Aerospace Bridge. The space bridge is covered by two large overhead bridges from east and west and north and south. , islands, corridors criss-cross, navigation in such a complex situation prone to failure, can not be accurately positioned. We under the bridge to the island by deliberately deviating from the navigation route to test the time of re-planning the route, and then you can see the delay of mobile positioning time.
After several rounds of driving around the island, it was found that after intentionally deviating from the planned route, Xiaomi 8 replanned the route faster, and the iPhone X and Samsung S9 took a little longer.
And in the test, iPhone X and Samsung S9 have obvious positioning delays. When they have turned their heads, iPhone X and Samsung S9 positioning is still not before turning their heads.
From the actual tests, we found that compared with the iPhone X and Samsung S9, the dual-frequency GPS millet 8 is not only more accurate in positioning, but also has lower positioning delay, and can effectively avoid the situation of 'walking' in actual navigation. Dual-band GPS is not a gimmick, but a practical function with obvious effects.
Why is Millet 8's dual-frequency GPS more accurate than traditional mobile phone positioning?
Xiaomi 8 is the world’s first smart phone equipped with dual-frequency GPS. Compared with the mobile phones currently using single-frequency GPS, Xiaomi 8 supports dual-frequency positioning using the L1 band of 1575.42 MHz and the L5 band of 1176.45 MHz. Software that uses location-based services, such as maps, cars, etc., can effectively avoid problems with inaccurate positioning.
GPS positioning is mainly based on the time from when the signal is transmitted from the satellite to the mobile phone to determine the specific location. For single-frequency GPS, there are two main factors that affect the positioning accuracy:
Signal passing through ionosphere causes delay
The ionosphere in the atmosphere is filled with ions and electrons under the irradiation of sunlight, which has a serious impact on the electromagnetic signal of the GPS signal. The signal emitted by the GPS through the ionosphere causes refraction, thus affecting the transmission time, resulting in positioning deviation.
Because the ionosphere has different effects on the L1 and L5 frequency band signals, the dual-frequency GPS millet 8 can be used independently of other factors. By comparing the delays of the two signals, the error caused by the ionosphere is eliminated by calculation.
Ground Construction Blocking 'Multipath Effect'
When positioning in cities or rivers, lakes, and seas, metal, water, and glass are all good reflectors of GPS signals. In the above scenario, GPS positioning is used. In addition to the signals transmitted from the GPS satellites after straight transmission, Will receive one or more signals reflected by the surrounding terrain.
In this way, the mobile phone receives multiple signals from direct and reflected signals, causing the peaks to deviate from the direct real position after multiple signal phases are superimposed on each other, resulting in a significant deviation, thereby reducing the accuracy of the distance calculation between the satellite and the receiver. It may even cause the satellite signal to disappear.
The dual-frequency GPS positioning of Xiaomi 8, because the code rate of L5 frequency band GPS signal is 10 times that of L1 frequency band, so the waveform of L5 frequency band signal is narrower, and the superposition effect between direct and reflected signals is not easy to occur, and it is easier to separate the most accurate. Direct signal to calculate the exact location of the phone.
Xiaomi 8 is the world’s first dual-band GPS mobile phone that can achieve ultra-precise positioning. It can help all applications that require location services to improve the user experience. The conference mentioned that dual-frequency GPS can improve the positioning accuracy by 3-5 compared to traditional single-frequency GPS mobile phones. Times. So what's the actual effect?
This time, we have selected four high-frequency scenes that require the use of positioning services to be measured, including cell phones, micro-channels, real-time sharing, walking navigation, driving navigation, and adding two single-frequency GPS flagship mobile phones as reference.
Scenario 1: Comparison of car location
The furthest distance in the world is that you cannot find a driver when you are called a car. The driver can't find you. The inaccurate positioning often leads you to such an embarrassment that Lunan drivers are on Lubei. And this happens because Single-frequency GPS signals are caused by architectural obstructions and glass reflections in building-intensive areas. To demonstrate the performance of dual-frequency GPS in complex environments, we have also selected test sites in the China World Trade Center (CBD) with many high-rise buildings and many glass curtain walls.
Three testers stood at the same location on the A exit of the Guomao Subway Station. The three mobile phones simultaneously opened the same car calling software for positioning. The iPhone X and the Samsung S9 both showed certain deviations. The iPhone X shifted to the nearby China World Mall. The Samsung S9 simply drifted to the Yintai Center in the south. Only the Xiaomi 8 can be accurately positioned to the actual location.
Scenario 2: Comparison of real-time location of WeChat sharing
When he does not know exactly where he is and when you are looking for him again, WeChat share real-time location is a good solution. Of course, the premise of all this is positioning is accurate enough. Our three testers stood Jianwai SOHO in front of the same location, open the WeChat share location at the same time.
As a result, only the millet 8 is accurately positioned to the correct position, the iPhone X has a slight deviation, and the Samsung S9 has once again experienced a large positional shift.
Scenario 3: Comparison of walking navigation
To go to a nearby restaurant in a strange city, it is often necessary to use walking navigation. Three testers also set off from Jianwai SOHO and walked to the nearby Jinzhou Bank to test whether the navigation guidance of the three mobile phones is accurate. At the same starting point, use The same map software, three mobile phones give the same planning route.
In the process of walking navigation, Samsung S9 and iPhone X also showed a clear positioning drift, the tester could not accurately obtain their true position, the navigation direction was wrong, and the actual walking trajectory deviated from the planned route. The millet 8 was the shortest, almost No "due" phenomenon due to positioning offset.
As shown in the figure below, iPhone X and Samsung S9 have obvious 'wrap around' phenomenon, and even appear to pass through the building. Actually, this is not the actual travel route, but is due to the positioning offset. The route trajectory is a road map composed of positioning points for each positioning of the mobile phone during the course of travel. The more 'routes' appearing, the more errors in locating offsets appear in the process of walking navigation.
Scenario 4: Comparison of re-planning speeds of yaw route
When navigating in the car, there are often cases where we have already opened the intersection and the navigation prompts. We will put three mobile phones in the same car and test it on the Beijing Aerospace Bridge. The space bridge is covered by two large overhead bridges from east and west and north and south. , islands, corridors criss-cross, navigation in such a complex situation prone to failure, can not be accurately positioned. We under the bridge to the island by deliberately deviating from the navigation route to test the time of re-planning the route, and then you can see the delay of mobile positioning time.
After several rounds of driving around the island, it was found that after intentionally deviating from the planned route, Xiaomi 8 replanned the route faster, and the iPhone X and Samsung S9 took a little longer.
And in the test, iPhone X and Samsung S9 have obvious positioning delays. When they have turned their heads, iPhone X and Samsung S9 positioning is still not before turning their heads.
From the actual tests, we found that compared with the iPhone X and Samsung S9, the dual-frequency GPS millet 8 is not only more accurate in positioning, but also has lower positioning delay, and can effectively avoid the situation of 'walking' in actual navigation. Dual-band GPS is not a gimmick, but a practical function with obvious effects.
Why is Millet 8's dual-frequency GPS more accurate than traditional mobile phone positioning?
Xiaomi 8 is the world’s first smart phone equipped with dual-frequency GPS. Compared with the mobile phones currently using single-frequency GPS, Xiaomi 8 supports dual-frequency positioning using the L1 band of 1575.42 MHz and the L5 band of 1176.45 MHz. Software that uses location-based services, such as maps, cars, etc., can effectively avoid problems with inaccurate positioning.
GPS positioning is mainly based on the time from when the signal is transmitted from the satellite to the mobile phone to determine the specific location. For single-frequency GPS, there are two main factors that affect the positioning accuracy:
Signal passing through ionosphere causes delay
The ionosphere in the atmosphere is filled with ions and electrons under the irradiation of sunlight, which has a serious impact on the electromagnetic signal of the GPS signal. The signal emitted by the GPS through the ionosphere causes refraction, thus affecting the transmission time, resulting in positioning deviation.
Because the ionosphere has different effects on the L1 and L5 frequency band signals, the dual-frequency GPS millet 8 can be used independently of other factors. By comparing the delays of the two signals, the error caused by the ionosphere is eliminated by calculation.
Ground Construction Blocking 'Multipath Effect'
When positioning in cities or rivers, lakes, and seas, metal, water, and glass are good reflectors of GPS signals. In the above scenario, GPS positioning is used. In addition to the signals transmitted from GPS satellites, they are transmitted through a straight line. Will receive one or more signals reflected by the surrounding terrain.
In this way, the mobile phone receives multiple signals from direct and reflected signals, causing the peaks to deviate from the direct real position after multiple signal phases are superimposed on each other, resulting in a significant deviation, thereby reducing the accuracy of the distance calculation between the satellite and the receiver. It may even cause the satellite signal to disappear.
The dual-frequency GPS positioning of Xiaomi 8, because the code rate of L5 frequency band GPS signal is 10 times that of L1 frequency band, so the waveform of L5 frequency band signal is narrower, and the superposition effect between direct and reflected signals is not easy to occur, and it is easier to separate the most accurate. Direct signal to calculate the exact location of the phone.
