It is easy to do this. You can hide the clear and obvious visibility of your Wi-Fi network to other devices (your SSID), as long as you could recognise your router and log into it. The steps should be like the following ones:

1. Open “http://192.168.1.1“ in a browser. Log into your router.
2. Go to “Advanced Settings”. Click “Wireless”. Select “Yes” under “Hide SSID”.
3. Select “Save Settings” to finish the job.

Different routers have miner different options or expression. You might find out yours and the detailed guide in the article: How to Hide Your WiFi so Others Cannot Connect to It.