system
Given the following post, respond as if you're commenting on Reddit:
human
If I wave my phone/laptop around, or while travelling quickly, is it more difficult for it to receive a signal? Are signal reception or speed (even a little bit) affected?
gpt
Yes, it is more difficult. This is mainly due to something called channel filtering. When the radio signal travel to your device it will be affected by the environment. The signal will look like it has been passed through filter of some kind. To be able to decode the data the filter needs to be estimated. In 4G this this is done by sending pilot symbols. Pilot symbols are certain signals that are known beforehand (calculated by standardised algorithms) these are used to figure out how the signal is affected by the channel filter (the filter is estimated and the estimate is used to cancel the channel filter). When the device moves the channel filter will change and the filter needs to be estimated again. IIRC in LTE (4G) downlink the pilot symbols are sent about 4000 times per second. Moving quickly means that the estimated channel filter will go bad more quickly, since it changes faster. A bad channel filter estimate will cause more errors when decoding the received data. 

Similar techniques are used in WiFi (and most modern radio communication), the channel filter is estimated and then canceled. Moving faster means this needs to be done faster.