After Firmware update keeps rebooting my galaxy s4 I recently updated my galaxy s4, and since then it keeps randomly rebooting. I have tried google for some solutions. I have tried a number of steps, such as taking battery out, clearing the cache, restarting the phone, deleting some recently downloaded apps but none of these steps have worked? 

Does anyone else have any knowledge why this might be occurring? Or what I should do? Thank you.

Update 28/10/2014

After doing a factory reset the issue seems to have gone away, leading me to believe it must have been corrupted at some point downloading files/apps on to my phone.
I would do something else. Chances are high your firmware has an issue. Go to http://samsung-updates.com/, select your device and search for your provider. Download the full firmware (about 1.6 gb) unzip(only once). Get yourself Odin(its for windows only). Its on xda everywhere.

A wipe data and wipe cache from recovery mode would be helpful here.
Hold on power button and volume up fore a while to go there, navigate using volume buttons. hit ok using power button.

Put your phone in download mode. (Turn off, hold down power button and volume down for a while, hit power up when the message appeared).
Connect your phone to the pc. Odin should see it now. In Odin you have a bunch of buttons on the right, select the second from the top on the right there. Navigate to your unzipped firmware image. (A .tar.md5 file) select it. Hit start after the file loaded. Do not touch your setup during flashing.

Good luck!

Do not try to flash firmware that isn't designed for your phone. It can destroy it. (Worst case). You can hit getprop in a shell on the device to get all information about your device. The exact device type, firmware version, provider shortcut and so on.

Another approach is to use Samsung Kies. Kies allows you to do firmware updates and used to flash every system partition on the device, not just the changes as the ota does. If you already are at the newest firmware, it might not work cause there's no update.