Offline page monitoring

• US 6,243,561 B1
• Filed: 10/13/1998
• Issued: 06/05/2001
• Est. Priority Date: 10/13/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Sih, Gilbert C., Agrawal, Avneesh, Zou, Qiuzhen, Zhang, Haitao, Butler, Brian K.
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US09/172,068
• Time in Patent Office: 966 Days
• Field of Search: 455/38.1, 455/35.1, 455/38.2, 455/38.3, 455/458, 375/206, 370/18, 370/335
• US Class Current: 340/7.42
• CPC Class Codes: H04B 1/70751 using partial detection H04B1/70758 takes precedence
• CPC Class Codes: H04B 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
• CPC Class Codes: H04B 1/70775 Multi-dwell schemes, i.e. multiple accumulation times
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A novel and improved method for performing paging is described. In one embodiment of the invention a searcher is used to detect spread spectrum signals. Samples received RF signals are stored in a sample buffer. During standby mode, the samples are gathered during paging slots assigned to the mobile. A set of searches are performed on the samples, and if pilot signals are detected additional demodulation is performed to detect paging messages. The resulting set of demodulation data may be combined to increase detection. After a page message has been detected, additional demodulation resources may be activated to processes more complete page messages, or other information channels. In one embodiment of the invention, the searcher includes a demodulator to perform quick page detection without the use of finger elements to reduce idle mode power consumption.

Claims

1. A system for receiving pages, comprising:

(a) a receiver means for receiving first receive samples;

(b) a storage unit for storing said first receive samples;

(c) a means for turning off said receiver means after said first receive samples have been stored, and for turning it on at a predetermined time;

(d) an enhanced searcher for detecting the correlation energy of a pilot channel and for demodulating a first paging channel within said first receive samples; and

(e) a demodulation element for demodulating a second paging channel within other receive samples.

2. The system as set forth in claim 1, further comprising a decoder for decoding soft decision data from said demodulation element.

3. The system as set forth in claim 1, further comprising an RF unit for generating said receive samples.

4. The system as set forth in claim 1, further comprising a control unit for activating said searcher during quick page slots, and for activating said demodulation unit during full paging slots when a quick page message is received.

5. The system as set forth in claim 1, wherein said combined searcher comprises:

(a) a first processing element for despreading a pilot channel;

(b) a second processing element for despreading said pilot channel and for despreading said first paging channel;

(c) a phase adjustment demodulation circuit for rotating said first paging channel data using said using pilot channel from said first processing element; and

(d) a correlation energy circuit for calculating correlation energy for said second processing element.

6. The system of claim 5, wherein the phase adjustment circuit comprises a two-dimensional vector dot product or cross product between data and pilot complex baseband signals.

7. The system as set forth in claim 1, further comprising a combiner circuit for diversity combining demodulated data, wherein:

(a) said searcher performs multiple demodulations within said stored data for said first paging channel; and

(b) said combiner combines soft decision data from said multiple demodulations.

8. The system of claim 7, wherein said combiner comprises an accumulator.

9. A method for receiving pages, comprising the steps of:

(a) receiving first receive samples;

(b) storing said first receive samples;

(c) turning off said receiver means after said first receive samples have been stored, and turning it on at a predetermined time;

(d) detecting the correlation energy of a pilot channel and for demodulating a first paging channel within said first receive samples;

(e) demodulating a second paging channel within other receive samples; and

(f) diversity combining demodulated data, by;

(1) performing multiple demodulations within said stored data for said first paging channel; and

(2) combining soft decision data from said multiple demodulations.

10. The method as set forth in claim 9, wherein said searching step comprises the steps of:

(a) searching a pilot channel;

(b) despreading said pilot channel;

(c) despreading said first paging channel; and

(d) demodulating said first paging channel by projecting said first paging channel despread data onto said pilot channel despread data.

11. The method as set forth in claim 9, wherein said searching step comprises the steps of:

(a) demodulating a pilot channel;

(b) demodulating said pilot channel;

(c) demodulating said first paging channel;

(d) calculating correlation energy from pilot channel data;

(e) projecting first paging channel data using pilot channel data; and

(f) calculating a correlation energy for said pilot information channel data.

12. The method as set forth in claim 9, further comprising the step of accumulating demodulated data, wherein:

(a) multiple demodulations within said stored data for said first paging channel are performed, and

(b) said accumulation step accumulates soft decision data from said multiple demodulations.