Receiver for receiving a spectrum dispersion signal

• US 20020054622A1
• Filed: 12/27/2001
• Published: 05/09/2002
• Est. Priority Date: 03/31/1998
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Osamu Hasegawa, Shigeyuki Sudo, Toshiya Eguchi
• Inventors: Sudo, Shigeyuki, Hasegawa, Osamu, Eguchi, Toshiya
• Granted Patent: US 7,035,309 B2
• Time in Patent Office: Days
• 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 intermittent receiving control in which a suspension period of intermittent receiving operation is managed by first timer means and a phase of spreading code for a received signal is calculated upon resumption of receiving operation, a state value of despreading code generating means after a predetermined time being set on the basis of said calculated value, an elapse of said predetermined time being managed by second timer means started newly upon the resumption of the receiving operation, demodulation operation of a spread signal being resumed after the elapse of said predetermined time, a continuation time of the demodulation operation being adjusted every time on the basis of said calculated value.

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 on the basis of said calculated phase of spreading code; and

intermittent receiving control means for controlling to start counting of said second timer means when said storage means starts storage operation and to cause said code generating means to start operation thereof on the basis of 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, 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, on the basis of said calculated code phase; and

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

and 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.