Take a look at this thread, Kevin Camp wrote some expressions that allow you to tie the emitters position to a null(which you would parent the camera). The particles would move with the null and the camera, so as the camera moves the particles would move exactly as much, ie, they wouldn't appear to move, but they would always be locked to the camera. If you did rotate your null, they would appear to move in regards to rotation.
Another method is just to make the Producer Radius really large, though that may mess up the look of your animation.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.