Receiver for receiving a spectrum dispersion signal
First Claim
1. A receiver for receiving a spread spectrum signal and including means for generating a code for dispreading, comprising:
- a first timer;
a second timer; and
intermittent receiving control means for controlling intermittent operation of said receiver, wherein said intermittent receiving control means, in response to said first timer, controls a suspension period of intermittent receiving operation of said receiver, in response to said second timer, resumes receiving operation of said receiver by calculating a phase of spreading code for a received signal and setting a state value of dispreading code generating means based on the calculated phase of spreading code, and resumes demodulation operation of said receiver so as to demodulate a spread signal, and wherein a continuation time of the demodulation operation of said receiver is adjusted based on the calculated phase of spreading code.
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Accused Products
Abstract
A receiver for the CDMA system which reduces power consumption during a suspension period of intermittent receiving operation by monitoring a suspension period by a low-power timer so that a VC-TCXO, reference signal group generation and receiving units are turned off and a modem unit is set to a sleep state. Upon resumption of receiving operation, a high-accuracy timer is started to count a time period and part of a received signal is stored. A PN code phase of stored data is calculated during the time period to obtain an indication value for phase deviation. State vectors for short and long codes and a further reception time are calculated based on the indication value. When the high-accuracy timer counts the time period and produces 0V(d), demodulation operation by a rake demodulation, demultiplexing, and descrambler units is started and is continued during the reception time.
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Citations
13 Claims
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1. A receiver for receiving a spread spectrum signal and including means for generating a code for dispreading, comprising:
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a first timer;
a second timer; and
intermittent receiving control means for controlling intermittent operation of said receiver, wherein said intermittent receiving control means, in response to said first timer, controls a suspension period of intermittent receiving operation of said receiver, in response to said second timer, resumes receiving operation of said receiver by calculating a phase of spreading code for a received signal and setting a state value of dispreading code generating means based on the calculated phase of spreading code, and resumes demodulation operation of said receiver so as to demodulate a spread signal, and wherein a continuation time of the demodulation operation of said receiver is adjusted based on the calculated phase of spreading code. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of receiving a spread spectrum signal intermittently, comprising the steps of:
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receiving said spread spectrum signal;
demodulating said spread spectrum signal received by said receiving step;
starting a first timer when said receiving step changes from a suspension state to a receiving state, wherein an accuracy of a second timer is higher than an accuracy of the first timer and a chip rate of said spread spectrum signal;
controlling said receiving state and said suspension state based on a count by the first timer and the second timer; and
calculating a timing error which occurred due to the first timer, wherein said controlling step controls a demodulation unit so as to resume demodulation operation so that dispreading said spread spectrum signal attains synchronization based on the timing error after a receiver changes from said suspension state to the receiving state. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A mobile communication terminal, comprising:
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a receiver for receiving a spread spectrum signal and including means for generating a code for dispreading;
a demodulator;
an intermittent receiving control means for controlling intermittent operation of said receiver; and
at least three timers including a first timer, a second timer and a third timer, which are connected to said intermittent receiving control means, wherein said intermittent receiving control means, in response to said first timer, controls a suspension period of intermittent receiving operation of said receiver, in response to said second timer, resumes receiving operation of said receiver by calculating a phase of spreading code for a received signal and setting a state value of dispreading code generating means based on the calculated phase of spreading code, and resumes demodulation operation of said receiver so as to demodulate a spread signal, and wherein a continuation time of the demodulation operation of said receiver is adjusted based on the calculated phase of spreading code and provided to the third timer, which controls the continuation time of the demodulation operation.
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Specification