Ask for the direction positioning principle of Bluetooth 5.1

freebsder

Ask for the direction positioning principle of Bluetooth 5.1 [Copy link]

 

Regarding the directional positioning of Bluetooth 5.1, I have looked online and found that there are basically no in-depth articles. Most of them are just superficial introductions. I feel that this function seems to be very awesome. I would like to ask an expert to help me solve this problem!

soso

Radio direction finding is derived from: https://www.eeworld.com.cn/wltx/2019/ic-news022821245.html I hope professionals can explain it in detail.

懒猫爱飞

1) ICs that support 5.1 have been released, including Dialog and Nordic. 2) AOA and AOD are just a feature of 5.1. Although the chip has them, the SDK has not yet been fully developed. 3) In addition, two or more antennas may be required, and there are certain requirements for the panel. It is estimated that it will not be mature in one or two years.

freebsder

Lazy Cat Loves Flying published on 2019-4-13 22:20 1) ICs that support 5.1 have been released, including Dialog and Nordic. 2) AOA and AOD are just a feature of 5.1. Although the chip has them, the SDK does not yet have them...

Yes, there is a lot of hype, and the information provided by various companies is basically just a generalization of the concept. I feel that this function should have applications, so I want to understand the principle.

topwon

The principle of Beacon signal AOA angle measurement is to use the antenna array to measure the phase difference Φ when the signal arrives at different antennas, and then calculate the angle θ between the signal source and the antenna array. Convert the phase difference into Angle of Arrival Last step is converting the phase shift (Φ) back to AoA (Θ). Keep in mind if Φ is negative, this means that antenna 2 is ahead of antenna 1 and the Θ. The angle between the incident wave and antenna array is Θ. Base on the picture below we know that the sin(Θ) = r/d, and d is the distance between antenna 1 and antenna 2 which is known. Then all we need to find out is r. r is the distance to antenna 2 that the incident wave needs to travel after arriving at antenna 1. We have found that the phase difference between antenna 1 and antenna 2 is Φ, so the extra distance r is equal to wavelength of the incoming signal * Φ/(2Π). r= Λ* Φ/(2Π) Therfore Θ can be represented as below:

topwon

The reply I just sent is still under review. You can go to TI's official website to search for the introduction of AOA. It seems that there is a matching DEMO board (BOOSTXL-AOA) that can be purchased and tested (but according to the user's question, the angle jitter range is still about 20 degrees. TI's response is that the user may need to further add algorithm filtering).

topwon

, this is quite expensive to buy as a finished product, 1200 yuan per piece. I plan to use the provided design documents to make my own boards and buy the components.

topwon

A more detailed introduction to the original text address: http://dev.ti.com/tirex/content/ ... etag=s_pctim_aiomsg, and http://dev.ti.com/tirex/#/ Search for "Angle of Arrival BoosterPack" in the search bar. I don't know if it can be approved.

freebsder

topwon posted on 2019-4-15 13:54 A more detailed introduction to the original address: http://dev.ti.com/tirex/content/ ... etag=s_pctim_aiomsg, and http://dev ...

Thank you! It is indeed much more detailed than other introductions!

topwon

You’re welcome. I happened to be looking into Beacon positioning technology these past two weeks. Let’s learn together.

soso

topwon posted on 2019-4-15 15:59 You are welcome. I happened to be looking at the Beacon positioning technology in the past two weeks. Let’s learn together.

The forum is planning to work on Bluetooth recently. If you have time, come and work on it together

topwon

soso posted on 2019-4-15 18:10 Forum I am planning to work on Bluetooth recently. Let's work on it together when we have time

Haha, I have basically not done anything with Bluetooth. I have made some Zigbee products before. It's just that the company is considering making an indoor positioning product recently, so I started to study some Beacon positioning technology. Currently, the products on the market mainly use RSSI ranging (actually the distance in free space is estimated) plus multi-point triangulation. I think the accuracy is a bit uncertain when used in complex indoor blocking environments (the uncertainty of attenuation caused by blocking should affect the estimated distance value). If RSSI ranging is combined with AOA angle measurement for positioning, the accuracy should be improved.

soso

topwon posted on 2019-4-16 17:23 Haha, I have basically never worked with Bluetooth. I have made some Zigbee products before, but the company is considering making an indoor positioning product recently, so...

I am currently doing an evaluation of a Bluetooth 5.0 board: https://en.eeworld.com/bbs/elecplay/content/109 If you are interested, you can pay attention to it. I also hope to give you more advice.

QWE4562009

Lazy Cat Loves Flying published on 2019-4-13 22:20 1) ICs that support 5.1 have been released, including dialog and nordic. 2) AOA and AOD are just a feature of 5.1. Although the chip has them, the SDK does not yet have them...

Whose company is NRF  

悟我啊

Have you evaluated Telink's AOA/AOD?

悟我啊

QWE4562009 posted on 2019-5-6 10:25 Who is NRF

The one starting with n is Nordic.