Rake receiver and finger management method for spread spectrum communication

A method for finger management in a RAKE receiver, the method comprising the steps of:

• receiving a plurality of signals at the RAKE receiver, the RAKE receiver having more than one finger;
• assigning each finger to one signal of the plurality of signals;
• detecting a low delay-spread condition of the plurality of signals;
• and
• in response to the low delay-spread condition, controlling a time position of one or more fingers to prevent convergence of two fingers at a common time position, said controlling step including substeps of:
• varying a time position of each finger according to assigned signal time position;
• controlling the time position of a first finger;
• and
• maintaining the time position of a second finger at a fixed predetermined time difference from a time position of the first finger.

A method for finger management in a RAKE receiver, the method comprising the steps of:

• receiving a plurality of signals at the RAKE receiver, the RAKE receiver having more than one finger;
• assigning a first finger and a second finger to respective signals of the plurality of signals;
• determining a time separation between timing of the first finger and timing of the second finger;
• and
• maintaining the time separation greater than a threshold value.

A receiver for receiving a multipath signal, the multipath signal including at least a first ray having first ray timing and a second ray having second ray timing, the receiver comprising:

• a first receiver circuit assignable to receive the first ray, the first receiver circuit including a time tracking circuit for controlling a time position of the first receiver circuit in accordance with the first ray timing;
• a second receiver circuit assignable to receive the second ray, the second receiver circuit including a time tracking circuit for controlling a time position of the second receiver circuit in accordance with the second ray timing;
• a control circuit which assigns the first receiver circuit to receive the first ray and assigns the second receiver circuit to receive the second ray, the control circuit determines an adjusted first receiver circuit position in response to a variation in the first ray timing;
• and
• a collision prevention circuit for preventing convergence of the time position of the first receiver circuit and the time position of the second receiver circuit about a common time position, the collision prevention circuit comprises:
• a circuit for determining a time difference between the adjusted first receiver circuit position and the time position of the second receiver circuit;
• and
• an adjusting circuit for adjusting the time position of the first receiver circuit to the adjusted first receiver circuit position only when the time difference exceeds a predetermined threshold.