Is the 2.4GHz proprietary mode of nRF 52/53/54 series still DSSS?

[Jin Lin]

Hi, Nordic and all expects.

I am checking whether EN 300 328 can be used for testing 2.4G proprietary mode of nRF 52/53/54 series; EN 300 328 is a popular RF standard for certifying BLE and WiFi devices. According to EN300328, the device/equipment using modulation or spreading technologies is applicable to EN 300 328, such as FHSS, DSSS, OFDM, etc.

However, I am confused about whether the 2.4GHz proprietary mode of nRF 52/53/54 series is still to be DSSS (Direct Sequence Spread Spectrum) or not?

I heard from some peoples that the proprietary mode of nRF chips is not FHSS, not spread spectrum, so the proprietary mode of these chips cannot use EN 300 328 but only EN 300440 standard for the compliance test. But in my knowledge, all popular wideband data transmittion technologies are embeding spread spectrum technology to make the signal can be emitted on the frequency band like 2.4G, 5G, etc. 

Please help to clarify whether the proprietary of nRF chips is still use DSSS or not? if not, which spectrum technology using? Thank you so much.

[fredrikgk]

Hi Jin, Enhanced Shockburst (ESB) uses wide band modulation and thus fulfils the requirements in EN 300 328 section 4.3.2 "Requirements for other types of Wideband Data Transmission". ESB on 52/53/54 can thus be certified under EN 300 328 similar to Bluetooth Low Energy. 

Best regards,
Fredrik

[Jin Lin]

Thank you so much Fredrik for your clarification.

[Kwu]

Hi Fredrik,

Could you explain how ESB work?  Does it use GFSK and apply spread spectrum?

Thanks

[fredrikgk]

Hi Jin,

EBS typically uses Nordic 1 Mbps or 2 Mbps proprietary modes which are GFSK. No spread spectrum techniques are used, but that is not required to certify under EN 300 328.

Best regards,
Fredrik