Receiver for receiving a spectrum dispersion signal

• US 6,363,101 B1
• Filed: 03/26/1999
• Issued: 03/26/2002
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Eguchi, Toshiya, Hasegawa, Osamu, Sudo, Shigeyuki
• Primary Examiner(s): Le, Amanda T.
• Application Number:
  US09/277,164
• Time in Patent Office: 1,096 Days
• Field of Search: 375/140, 375/147, 375/153, 370/311, 370/318, 370/335, 455/425, 455/574
• US Class Current: 375/147
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70756 Jumping within the code, i.e. masking or slewing H04B1/70758 takes precedence
• CPC Class Codes: H04B 2201/70709 with discontinuous detection
• CPC Class Codes: H04W 52/029 reducing the clock frequency of the controller
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A receiver for the CDMA system, in order to reduce a power consumption during a suspension period of intermittent receiving operation, monitors a suspension period t1 by means of a low-power timer 51 so that a VC-TCXO 1, a reference signal group generation unit 2 and a receiving unit 3 are turned off and a modem unit 4 is set to a sleep state. Upon resumption of receiving operation, a high-accuracy timer 44 is supplied with a start (d) to require counting of time t3 and a part of a received signal is stored. A PN code phase of stored data is calculated in a PN code phase calculator 46 during a period t3 to obtain an indication value i for a phase deviation. State vectors for short code and long code and further a reception time t4 are calculated on the basis of the indication value i to be set. When the high-accuracy timer 44 counts t3 and produces 0V(d), demodulation operation by a rake demodulation unit 40, a demultiplexing unit 41 and a descrambler unit 42 is started in accordance with the setting and is continued during the reception time t4.

Claims

1. A receiver for receiving a spread spectrum signal and including means for generating a code for despreading, comprising:

a first timer;

a second timer; and

intermittent receiving control means for controlling intermittent operation of said receiver,

wherein said intermittent 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 despreading 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,

wherein a continuation time of the demodulation operation of said receiver is adjusted based on the calculated phase of spreading code.

2. A receiver for receiving a spread spectrum signal and including means for generating a code for despreading, comprising:

first timer means started when a receiving state is changed to a suspension state;

second timer means started when receiving operation is resumed from the suspension state and for counting a length of time A;

storage means for storing a received signal of a predetermined length in the form of digital data;

code phase calculation means for calculating a phase of spreading code relative to the received signal stored in said storage means;

state vector calculation means for calculating a state vector of said code generating means corresponding to a code phase after an elapse of time corresponding to said length of time A based on said calculated phase of spreading code; and

intermittent receiving control means for controlling start of counting of said second timer means when said storage means starts storage operation, and controlling said code generating means to start operation thereof based on the calculated result of said state vector calculation means, when said second timer means is overflowed.

3. A receiver for receiving a spread spectrum signal according to claim 2, further comprising:

reception time calculation means for calculating a length of reception time B containing a slot period of a paging channel to be received from the time that said second timer means is overflowed and to which a predetermined receiving processing time is added, based on said calculated code phase; and

third timer means to which any length of time to be counted can be set,

wherein said intermittent receiving control means sets said length of time B calculated by said reception time calculation means to said third timer means when said second timer means is overflowed to start counting of said third timer means and starts said first timer means when said third timer means is overflowed.

4. A receiver for receiving a spread spectrum signal intermittently, having code generating means for generating a code for dispreading, comprising:

receiving means for receiving said spread spectrum signal;

first timer means started when said receiving means changes from a receiving state to a suspension state;

second timer means started when said receiving means resumes a receiving operation from the suspension state; and

intermittent receiving control means for calculating a phase of a spreading code for the spread spectrum signal received upon resumption of the receiving operation, calculating a state value of said code generating means after a predetermined time based on said phase of said spreading code, and resuming a demodulation operation of said spread spectrum signal based on said state value when a lapse of said predetermined time is detected by said second timer means,

wherein said intermittent receiving control means adjusts a continuation time of the demodulation operation based on said phase of said spreading code.

5. A receiver for receiving a spread spectrum signal intermittently, comprising:

a receiver which receivers said spread spectrum signal;

a first timer which operates when said receiver is in a suspension state;

a second timer which operates when said receiver is in a receiving state; and

a demodulation unit which starts to demodulate said spread spectrum signal when a lapse of a predetermined time from a start of a receiving operation is detected by said second timer.