LTE band 40 desensitization of Wi-Fi® devices

This technical note was prompted by concern from Wi-Fi Alliance® members that the newly introduced TDD LTE bands 40 and 41, which abut the 2.4 GHz ISM band, would interfere with Wi-Fi® operation.

This note describes an experimental setup whereby a reference TDD LTE signal can be introduced at varying frequency offsets and varying powers to ascertain the effect it has on the receive (RX) sensitivity, and therefore to performance, of a number of Wi-Fi devices.

The results show that some Wi-Fi devices are very susceptible to desensitization by the LTE signal and will incur a significant impact to their performance. Other devices are less susceptible, but all devices have the potential to having their performance adversely affected on all three Wi-Fi channels.