Another approach to restart your iPhone's wireless connection is to delete or forget your wireless network, then reconnect. This will allow your device to join to your Wi-Fi network for the first time as if it were the first time. Any flaws that may have caused your wireless network to become corrupted will be removed as well. Follow these steps to give it a shot:

1. From the Home screen, choose Settings.
2. Select Wi-Fi.
3. Next to the Wi-Fi network, you wish to forget or remove, tap the information icon (blue I
4. Select Forget This Network from the drop-down menu.
5. If you find any other stored Wi-Fi networks, delete/forget them as well to avoid any conflicts with your current Wi-Fi network.
6. Return to the Settings->Wi-Fi menu after restarting your iPhone.
7. To join or connect to your wireless network, turn on Wi-Fi and then touch the option to join or connect to your wireless network.