Channel interference

Question

I have a NRF52840 and wanted to know, how much of a signal gets into another channel in BLE.
I am going to explain what I mean so there is no confusion :). 
 The Bluetooth Channels are like following image shows:
 BLE channel 
 So there are 40 channel with a bandwitdth of 2MHz, and the center frequencies are 2 MHz apart. 
 Now let's suppose I am sending on channel 20. 
 How much of this signal would land in channel 19 / 21?
I got the following from the BLE specifications:
 Specs 
 I am not sure which row gives me the information I need. I hope you can help me.

Jørn · Accepted Answer

Hello ock 
 The lists you link to are the requirements for the receiver. They list the requirement for Carrier/Interference ratio, while maintaining a maximum bit error rate (BER) of 0.1%. If you look at the nRF52840 table 22.15.6 RX selectivity, our numbers are lower than the ones listed in the Bluetooth specification. This indicates our chip can handle worse C/I ratios than the requirement while maintaining a maximum BER of 0.1%. 
 If you look at table 22.15.4 of the nRF52840 product specification you find the Transmitter specification. Here it is stated that the ratio between transmit power 1 MHz from the carrier is -23dB when compared to the output power of the carrier. Similarly for 2MHz from the carrier frequency it is listed as -50dB compared to the carrier output power. These numbers are for the 1Mb/s PHY. 
 Considering each channel center frequency are 2 MHz apart, you could expect to see, in channel 19 and 21, a signal whose power is around -50dB compared to the output power in channel 20. 
 Best regards 
 Jørn Frøysa

Channel interference

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