If your other wireless devices connect just fine, & you're able to connect the PS3 to someone else's network, then that means a couple of things:
1. Your wireless router is working just fine.
2. Your PS3's wireless adapter is working just fine.
Which leads to the conclusion that you're missing a step when connecting the PS3 to your wireless network. Could be you have MAC filtering set up on the router & the PS3's MAC address isn't added in. Could be you're mistyping the Wi-Fi password. Could be your PS3 isn't getting a clear enough signal to connect to the router. Could be any number of things...but it's not a hardware issue on either end, which means it's a software or data-related issue.