Processor and method for weight detection in a closed loop diversity mode WCDMA system
AssigneeD.S.P.C. Technologies Ltd.
InventorItzhak Bergel
Life of this patent
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Abstract
A receiver and method for weight detection use received channel estimations and prior feedback information sent to a transmitter to estimate channel weights. The estimated channel weights may have been used by a base station to transmit diversity mode signals. In one embodiment, a trellis algorithm may be used to determine weights with no significant time-slot delay. The weights may be used to generate channel taps for use by a rake receiver in combining multipath components of received signals. In one embodiment, the receiver and method for weight detection may be suitable for use in closed loop diversity mode communication systems, including a Wideband Code Division Multiple Access (WCDMA) system.
Claims29
A method to detect a weight-set to process a spread spectrum channel comprising:
- determining a measurement probability for a weight-set from measurements of a current time-slot;
- determining a transition probability for the weight-set, the transition probability based at least on a change from a previously requested weight-set;
- calculating a weight-set metric for the weight-set based at least on the measurement and transition probabilities and a prior weight-set metric;
- and
- detecting a weight-set from a group of predetermined weight-sets based at least on the weight-set metric to process the current time-slot.
A processor comprising:
- a metrics calculation element to determine a measurement probability for a weight-set from measurements of a current time-slot, to determine a transition probability for the weight-set, the transition probability based at least on a change from a previously requested weight-set, and to calculate a weight-set metric for the weight-set based at least on the measurement and transition probabilities and a prior weight-set metric;
- and
- a weight detection element to select a weight-set from a group of predetermined weight-sets based at least on the weight-set metric to process the current time-slot.
A machine readable medium having program instructions stored thereon for performing a method of processing spread spectrum channels when executed within a digital processing device, the method comprising:
- determining a measurement probability for a weight-set from measurements of a current time-slot;
- determining a transition probability for the weight-set, the transition probability based at least on a change from a previously requested weight-set;
- calculating a weight-set metric for the weight-set based at least on the measurement and transition probabilities and a prior weight-set metric;
- and
- detecting a weight-set from a group of predetermined weight-sets based at least on the weight-set metric to process the current time-slot.
A code division multiple access (CDMA) receiver comprising:
- a dedicated channel measurement element to measure characteristics of current time slots of a CDMA channel;
- a metrics calculation element to calculate metrics for weight sets estimated to have been used in transmitting each of the current time slots, the metrics calculated from the measured characteristics of the current time slots;
- a weight detection element to select a weight set from a group of predetermined weight sets based at least on the metrics for the weight sets;
- and
- a channel tap calculator to generate channel taps from the selected weight-sets.
Dependencies are inferred from the claim text.