Mediatek Dimensity 9300 claim to support new GPS L1C and BDS B1C

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Media just launched their latest soc today. 

The latest website list specification for gnss bands. It claim to support "new L1C and B1C signal" . This is kind of unexpected because L1C is only broadcast by six satellite today.

And I wonder why B1C is listed as "new signal" . To my knowledge, B1C has two tracking method, BOC modulation and QMBOC modulation. The first one has better compatibility which existing device and reduce cost. The second method has better tracking performance. Maybe mediatak somehow find a way to track QMBOC. But it's hard to say.

As far as I know there are no way to tell if that device is using this new with GPSTest. 

Unless we implement the following conditions.

Mediatek has properly provide code type with GNSSMeasurement API.

GPS test can label signal with code type+frequency, which had to be done manually. 

Theoretically the L1CA code should be labeled as C, while L1C should be L or S(depend on which component to track). For B1C it doesn't matter really, because it's not a real new signal anyway. But we will have to find a device to test. Because chipmaker tend to randomly throw the code type

[Sean Barbeau]

Interesting - thanks for sharing!

Sean

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I've found more information on this. 

https://www.airoha.com/products/p/zy4r082hgNywp1bg

Airoha is a subsidiary of Mediatek that focus on GNSS chipset.

"AG3352 series adds the B1C and L1C frequency bands of Beidou-3 and GPS, making the positioning accuracy close to the dual-frequency standard."

And apparently dimensity 8300 also have L1C support. So for budget phone with SF GNSS design it could improve accuracy, kind of I think.

To be fair the B1C support is already widely adopted. 

L1C is good, but we will have to wait for 2024+ to have more GPS block III orbiting earth. As for now there's only 4 GPS III in the fleet. 😴

In Japan and China the entire QZSS constellation can broadcast L1C, so that add to 8 satellites.

Xiaomi Redmi K70E just is using 8300 with SF L1.

While Vivo X100 has 9300 with TF L1+L5+E5b/B2b. In the future Xiaomi 14T Pro will use 9300 which is expected.

I hope to purchase such a device in the future for testing. 

B2b/E5b PPP positioning and sensor-assisted location is exclusively on 9200/9300

'Sean Barbeau' via GPSTest <gpstest...@googlegroups.com> 于 2023年11月8日周三 上午2:32写道：

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[andras.l...@gmail.com]

" As for now there's only 4 GPS III in the fleet. 😴"       6!

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Oh I got it wrong. 

It's PNR 4, 11, 14, 18, 23, 28 in total. 6 satellites. 

If OCX control segment is coming online next year, US can start to replace the older Block IIR & IIF satellites finally.

Also I wonder why mediatek didn't mention QZSS L1C support. This should naturally occur when QZSS is such a perfect GPS replica (In signal design). Could be a ignorance I think. 

andras.l...@gmail.com <andras.l...@gmail.com> 于 2023年12月2日周六 下午6:21写道：

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