CDMA demodulation circuit and CDMA demodulation method
AssigneeNEC Corporation
InventorKoichi Tamura
Life of this patent
Estimating the term…
Abstract
To provide a CDMA demodulation circuit and a CDMA demodulation method capable of maintaining good receiving characteristics even in a mobile communication environment. A fading pitch estimation portion estimates a time at which a level of a received input signal drops due to fading by monitoring fluctuation in the level provided by a rake combining portion. Before the level drops, a finger path assignment control portion controls assignment of path timing to a fingers portion performed by a finger path assignment portion.
Claims20
A CDMA demodulation circuit comprising:
- delay profile calculating means for calculating delay profiles of received signals;
- path assigning means for assigning path locations to a plurality of fingers based on the calculation result obtained in said delay profile calculating means;
- the plurality of fingers to which the path locations are assigned by said path assigning means, the fingers de-spreading the assigned paths;
- and
- rake combining means for combining output of said plurality of fingers,
- wherein the CDMA demodulation circuit comprises reception controlling means that estimates a drop cycle of a reception level from the reception level combined by said rake combining means and that reduces degradation in receiving characteristics using the estimation result.
A CDMA demodulation method for a CDMA demodulation circuit comprising delay profile calculating means for calculating delay profiles of received signals;
- path assigning means for assigning path locations to a plurality of fingers based on the calculation result obtained in said delay profile calculating means;
- the plurality of fingers to which the path locations are assigned by said path assigning means, the fingers de-spreading the assigned paths;
- and rake combining means for combining output of the plurality of fingers,
- wherein the CDMA demodulation method comprises a first step of estimating a drop cycle of a reception level from the reception level combined by said rake combining means to reduce degradation in receiving characteristics using the estimation result.
Dependencies are inferred from the claim text.