Did this just start today? If so, then this could be due to the PSN Maintenance that is currently happening, you can see some more information here.
If this has been going on for longer, does this happen with all classes or just particular ones?
Are you using the Indirect Fire perk on your Support soldier? If so please try changing this perk, as this has been reported as causing a crash to occur.
Mine doesn't only happen with multiplayer it also happens during campaign. It is extremely annoying because I played for about 30 mins in campaign and unlocked a bunch of stuff, it froze and didn't save anything. All of my other games work fine, it is just bf4