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US 2007/0177656 A1Published application
Cdma receiving apparatus and method
AssigneeNEC Corporation
InventorsYasushi Maruta, Satoshi Oura, Shinya Muraoka
Life of this patent
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Abstract
A channel estimation circuit (12) of an individual CH path demodulation unit (1A-1L) performs a channel estimation from an individual CH. A channel estimation value correction circuit (22) of a shared CH path demodulation unit (2A-2L) then corrects a reception power fluctuation due to uplink transmission power control which is caused by the timing offset between the individual CH and the shared CH. The resultant data is used for the demodulation by a shared CH demodulation circuit (23).
Claims12
A CDMA receiving apparatus characterized by comprising:
- a radio reception unit which outputs a radio reception output in an uplink communication channel on which an individual channel occupied by each user and a shared channel shared among all users are multiplexed on the basis of a CDMA scheme, by performing signal processing for a radio band signal received by a reception antenna;
- a channel estimation circuit which receives a signal corresponding to an individual channel of an arbitrary user which is obtained by performing despreading operation for the radio reception output, and calculates a channel estimation value indicating phase and amplitude fluctuations due to a channel from phase/amplitude information after despreading of a known Pilot portion symbol;
- a channel estimation value correction circuit which corrects the channel estimation value from said channel estimation circuit on the basis of a reception power fluctuation due to uplink transmission power control which is caused by a timing offset between the individual channel of the user and the shared channel;
- and
- a shared channel demodulation circuit which demodulates a signal corresponding to the shared channel of the user which is obtained by performing despreading operation for the radio reception output on the basis of the channel estimation value corrected by said channel estimation value correction circuit.
2 more elements
A CDMA receiving apparatus according to claim 4, characterized by further comprising
- a path detection circuit which detects path delays associated with an individual channel and shared channel of the user from the radio reception output,
- an individual channel despreading circuit which outputs a signal corresponding to the individual channel of the user by performing despreading operation for the radio reception output on the basis of the path delay of the individual channel of the user, and
- a shared channel despreading circuit which outputs a signal corresponding to the shared channel of the user by performing despreading operation for the radio reception output on the basis of the path delay of the shared channel of the user.
A CDMA receiving method characterized by comprising:
- the radio reception step of outputting a radio reception output in an uplink communication channel on which an individual channel occupied by each user and a shared channel shared among all users are multiplexed on the basis of a CDMA scheme, by performing signal processing for a radio band signal received by a reception antenna;
- the channel estimation step of receiving a signal corresponding to an individual channel of an arbitrary user which is obtained by performing despreading operation for the radio reception output, and calculating a channel estimation value indicating phase and amplitude fluctuations due to a channel from phase/amplitude information after despreading of a known Pilot portion symbol;
- the channel estimation value correction step of correcting the channel estimation value calculated on the basis of a reception power fluctuation due to uplink transmission power control which is caused by a timing offset between the individual channel of the user and the shared channel;
- and
- the shared channel demodulation step of demodulating a signal corresponding to the shared channel of the user which is obtained by performing despreading operation for the radio reception output on the basis of the channel estimation value corrected in the channel estimation value correction step.
2 more elements
Dependencies are inferred from the claim text.