Certain aspects provide a method for determining decoding order and reconstruction weights for decoded streams to be cancelled in a MIMO system with successive interference cancellation, based on estimates of the channel characteristics, the received composite signal and parameters of the system. The RTOS executes at least a first and second task and uses a plurality of task priorities. A frequency conversion unit mixes the amplified signal with a local oscillation signal to thereby convert the radio signal having a radio frequency signal into the radio signal having an intermediate frequency signal, resulting in an intermediate frequency signal. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.