Digital key solution iteration: Bluetooth channel detection function added, thre

Electronic Enthusiast reports that in the process of rapid development of smart cars, digital keys have also become one of the "traffic" sources, with multiple manufacturers paying attention to digital key technology. Currently, several car models from manufacturers such as BMW, Mercedes-Benz, Audi, Tesla, and BYD have launched their own digital key solutions.

The potential of Bluetooth technology in the field of digital keys remains

Data shows that in 2023, the delivery of pre-installed standard digital keys for non-new energy passenger cars in the Chinese market (excluding imports and exports) reached 1.8535 million vehicles, with the penetration rate breaking through 10% for the first time. By 2030, the digital key installation rate for passenger cars in China is expected to exceed 80%. The "Latest Information on the Bluetooth Market in 2024" also indicates that 100% of newly manufactured smartphones support the activation technology of Bluetooth digital keys.

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The communication technologies used by digital keys include Bluetooth, NFC, and UWB. These three major technologies each have their characteristics and have jointly promoted the transformation of car keys from traditional physical forms to digitalization.

Specifically, Bluetooth technology is based on Bluetooth Low Energy (BLE) technology, with an effective working distance of about 10 meters, positioning accuracy at the decimeter level, and power consumption less than 20mA. Its working principle is based on Bluetooth technology, which uses wireless communication in the 2.4GHz ISM band, transmitting the unlocking command through wireless signals to the door lock to achieve remote unlocking. However, its security is relatively weaker compared to NFC and UWB.

NFC technology operates at a frequency of 13.56MHz, allowing two devices to exchange data within a few centimeters range during wireless communication, which can be used immediately upon touch. However, NFC technology also has its disadvantages, mainly limited by the communication distance (generally less than 10cm) which restricts the application scenarios.

UWB technology uses nanosecond-level ultra-narrow pulses for high-speed data transmission, with a working frequency of 3.1GHz to 10.6GHz, providing positioning and precise distance measurement functions. Currently, UWB technology is considered an important development direction for the next generation of automotive digital keys, but the technology is still in its early stages of development, and there is still a need for breakthroughs in cost and technical maturity.

As UWB technology develops, Bluetooth technology is also iterating. The emergence of Channel Sounding (Bluetooth channel probing function) compensates for the disadvantage of Bluetooth technology in positioning accuracy and is considered the next generation of Bluetooth positioning technology.

In the future, will Bluetooth technology compete with UWB technology in the field of digital keys, and will UWB technology replace Bluetooth technology to become the mainstream digital key technology? Industry insiders expressed their views when communicating with Electronic Enthusiast Network. They believe that Bluetooth technology and UWB technology each have their advantages and disadvantages. The advantage of Bluetooth technology is low power consumption, but its accuracy is not as good as UWB, while UWB technology is the opposite. The two may coexist in the future, with digital key manufacturers choosing to use a certain technology based on scenario needs. They stated that if the Channel Sounding function can bring a better application experience in the future, Bluetooth technology will have more advantages, even if its accuracy is not as good as UWB technology, it is sufficient for most scenarios.

Bluetooth chips continue to iterate, with Channel Sounding becoming one of the directions for new products.At the current stage, Bluetooth technology remains a mature and widely used wireless communication technology, and it also has a high proportion in digital car keys, being the mainstream solution. Faced with the development potential of Bluetooth technology in the field of digital keys, upstream chip manufacturers are also actively deploying, trying to gain market share by providing technical support.

In the second half of 2023, Goldspeed Electronics launched a brand-new automotive-grade high-performance, low-power Bluetooth BLE chip - SNJ32W103. This product uses an ARM Cortex M0+ core, with a maximum main frequency of 64MHz, supports BLE 5.1, and the sleep current can be as low as 0.3μA@25°C, with a power consumption of 6.3mA.

The official statement indicates that Goldspeed Electronics' Bluetooth digital key solution uses multi-node deployment, with one master node and multiple anchor nodes. The anchor nodes communicate with the master node through the CAN bus, the master node establishes a BLE connection with the mobile phone, and the anchor nodes assist the master node in positioning. The solution has high compatibility, strong anti-interference, and is safe and reliable.

Peach Core Technology's ING91870CQ is an automotive-grade low-power Bluetooth SoC chip, using a 40nm process, with a 48M main frequency and built-in 512KB eFlash, 128KB RAM. ING91870CQ also supports AoA/AoD.

In addition to low-power Bluetooth technology, with the introduction of the Channel Sounding feature, the Channel Sounding feature will also be added to Bluetooth digital keys. However, Channel Sounding is still in the exploratory stage at present.

The main advantage of Channel Sounding is the improvement of detection accuracy, and the stability and security have been enhanced, which is of great help to the welcome function of digital car keys. The welcome function requires Bluetooth technology to accurately perceive whether the user has entered the welcome area and the unlock area, to automatically unlock the car door in the unlock area, and to activate the turn signal flashing function, and it is also required to automatically lock after reaching the lock area.

Li Jiarong, Director of the Bluetooth Technology Alliance for the Asia-Pacific and Chinese Markets, said that this feature may solve the positioning challenges of digital keys in complex environments. The overall cost-effectiveness of this technology and its rich ecological foundation may further promote the development of Bluetooth in the field of vehicle networking, providing support for the realization of higher-level autonomous driving technology.

On the chip side, Lead Microelectronics has launched a digital key chip that supports the Channel Sounding positioning algorithm - L651 M/S, which integrates BLE5.4 and 2-way CAN FD, and also integrates two LINs, with LIN communication capabilities. In terms of the Bluetooth RF system, it supports 8 concurrent connections and optimizes for more than 5 listening nodes; RSSI stability RSSI accuracy is ±1dB at room temperature, ±1.5dB at full temperature, and the maximum transmission power is ±10dBm.

In addition to Lead Microelectronics, Huiding Technology also stated that the company's product series supporting the latest Bluetooth Channel Sounding standard will be launched soon.

It is not difficult to find that due to the advantages of technologies such as Bluetooth, NFC, and UWB, the industry has also seen the emergence of integrated solutions for digital car key technology. In the future, the market share of Bluetooth+NFC solutions, Bluetooth+UWB+NFC solutions, or UWB+NFC solutions will all be further increased.