The switch for the Pulse Field is in the bunker next to where the troopers lead you. Head on in and flip the switch.

After you flip the switch the Pulse Field will overload.

Once the Pulse Field is down, make your way to the enemy base. There are a few turrets that you can take out as you get closer. Take note that an allied soldier will blow the gate with a Mini Nuke when you get close enough.

As soon as the gate is down, head straight into the base and through the front door.

Once the enemy general is defeated, your own general will suddenly appear and give you a short speech. He will also explain that by passing this simulation you have earned access to the special armory.

After you exit the simulation, follow the scribe to the weapons cache and load up on the goodies.