METHOD FOR OPERATING BASE STATION TO SOLVE SPEECH DISABLE STATE BASED ON INTER-SPEECH SPHERE MOVEMENT OF MOBILE STATION IN ENLARGING SPEECH RADIUS LIMITED IN TIMING IN CODE DIVISION MULTIPLE ACCESS MOBILE COMMUNICATION SYSTEM

• US 6,415,152 B1
• Filed: 01/05/2000
• Issued: 07/02/2002
• Est. Priority Date: 01/09/1999
• Status: Expired due to Term

• Current Assignee: Hyundai Syscomm, Inc. (Hyundai Motor Group)
• Original Assignee: Hyundai Electronics Industries Co. Ltd. (SK Hynix Inc.)
• Inventors: Chung, Chae Hun
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): Yun, Eugene
• Application Number:
  US09/478,626
• Time in Patent Office: 909 Days
• Field of Search: 455/436, 455/438, 455/440, 455/442, 455/444, 455/450, 455/422, 455/449, 370/331, 370/335, 370/342
• US Class Current: 455/446
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

A method for operating a base station to solve a speech disable state based on the inter-speech sphere movement of a mobile station in enlarging a speech radius limited in timing in a CDMA mobile communication system. In a base station where a speech radius wider than that limited by a modem ASIC is partitioned by a predetermined radius unit into a plurality of speech spheres for the enlargement of the limited speech radius and channel elements are assigned to the partitioned speech spheres for transmission/reception of channels, a handoff operation is performed from an arbitrary channel element in the base station to a channel element assigned to a different speech sphere when a mobile station moves beyond an initial speech sphere during conversation with the arbitrary channel element. At this time, a reverse traffic channel is demodulated and remains at a standby state. Therefore, if the mobile station moves beyond the initial speech sphere above the predetermined radius unit, the demodulated reverse traffic channel is selected and utilized by the channel element assigned to the different speech sphere. This has the effect of preventing a speech disable state based on the inter-speech sphere movement of the mobile station.

Claims

1. In a method for operating a CDMA base station which partition a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the movement of a specific mobile station located in said first speech sphere to said second speech sphere, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) if an access channel is sent from said specific mobile station located in said first speech sphere, allowing said first signal processor to detect and demodulate said access channel synchronously with said first EVEN SECOND clock;

d) allowing said first signal processor to assign a traffic channel synchronously with said first EVEN SECOND clock and transmit it to said specific mobile station in said first speech sphere;

e) if a reverse traffic channel is sent from said specific mobile station in said first speech sphere, allowing said first signal processor to detect and demodulate said reverse traffic channel synchronously with said first EVEN SECOND clock;

f) allowing said first signal processor to measure a first bidirectional propagation delay time with said specific mobile station at an interval of predetermined time and compare the measured first bidirectional propagation delay time with a first threshold value;

g) allowing said first signal processor to repeatedly measure said first bidirectional propagation delay time if said first bidirectional propagation delay time is smaller than said first threshold value at said step f) and, if said first bidirectional propagation delay time is greater than or equal to said first threshold value at said step f), allowing said first signal processor to subtract said maximum bidirectional propagation delay value of said first speech sphere from said first bidirectional propagation delay time and set the subtracted result as a second bidirectional propagation delay time;

h) allowing said second signal processor to detect and demodulate said reverse traffic channel from said specific mobile station synchronously with said second bidirectional propagation delay time;

i) allowing said first signal processor to compare said first bidirectional propagation delay time with a second threshold value; and

j) selecting and utilizing said reverse traffic channel demodulated by said second signal processor if said first bidirectional propagation delay time is greater than or equal to said second threshold value at said step i).

2. The speech disable state solving method as set forth in claim 1, further comprising the steps of:

k) allowing said first signal processor to measure a third bidirectional propagation delay time with said specific mobile station;

l) allowing said first signal processor to compare said third bidirectional propagation delay time measured at said step k) with a third threshold value; and

m) returning to said step k) if said third bidirectional propagation delay time is smaller than said third threshold value at said step l) and stopping the demodulation operation of said first signal processor if said third bidirectional propagation delay time is greater than or equal to said third threshold value at said step l).

3. The speech disable state solving method as set forth in claim 1, further comprising the step of k), if said first bidirectional propagation delay time is smaller than said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said first signal processor and then returning to said step f).

4. The speech disable state solving method as set forth in claim 1, wherein said first to third threshold values are defined as follows:

maximum bidirectional propagation delay value of first speech sphere<

first threshold value<

second threshold value<

third threshold value<

maximum bidirectional propagation delay value limited by modem ASIC.

5. In a method for operating a CDMA base station which partitions a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the movement of a specific mobile station located in said second speech sphere to said first speech sphere, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) if an access channel is sent from said specific mobile station located in said-second speech sphere, allowing said second signal processor to detect and demodulate said access channel synchronously with said second EVEN SECOND clock;

d) allowing said first signal processor to assign a traffic channel synchronously with said second EVEN SECOND clock and transmit it to said specific mobile station in said second speech sphere;

e) if a reverse traffic channel is sent from said specific mobile station in said second speech sphere, allowing said second signal processor to detect and demodulate said reverse traffic channel synchronously with said second EVEN SECOND clock;

f) allowing said second signal processor to measure a first bidirectional propagation delay time with said specific mobile station at an interval of predetermined time, add said maximum bidirectional propagation delay value of said first speech sphere to the measured first bidirectional propagation delay time and set the added result as a second bidirectional propagation delay time;

g) allowing said second signal processor to compare said second bidirectional propagation delay time with a first threshold value;

h) returning to said f) if said second bidirectional propagation delay time is greater than said first threshold value at said step g) and allowing said first signal processor to detect and demodulate said reverse traffic channel from said specific mobile station synchronously with said second bidirectional propagation delay time if said second bidirectional propagation delay time is smaller than or equal to said first threshold value at said step g);

i) allowing said second signal processor to compare said second bidirectional propagation delay time with a second threshold value; and

j) selecting and utilizing said reverse traffic channel demodulated by said first signal processor if said second bidirectional propagation delay time is smaller than or equal to said second threshold value at said step i).

6. The speech disable state solving method as set forth in claim 5, further comprising the steps of:

k) allowing said second signal processor to measure a third bidirectional propagation delay time with said specific mobile station, add said maximum bidirectional propagation delay value of said first speech sphere to the measured third bidirectional propagation delay time and compare the added result with a third threshold value; and

l) allowing said second signal processor to repeatedly measure said third bidirectional propagation delay time if said third bidirectional propagation delay time is greater than said third threshold value at said step k) and stopping the demodulation operation of said second signal processor if said third bidirectional propagation delay time is smaller than or equal to said third threshold value at said step k).

7. The speech disable state solving method as set forth in claim 5, further comprising the step of k), if said second bidirectional propagation delay time is greater than said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said second signal processor and then returning to said step f).

8. The speech disable state solving method as set forth in claim 5, wherein said first to third threshold values are defined as follows:

first threshold value>

second threshold value>

third threshold value>

maximum bidirectional propagation delay value of first speech sphere.

9. In a method for operating a CDMA base station which partitions a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the location of a specific mobile station in a border area between said first and second speech spheres, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) allowing said first signal processor to set up the size of an access channel preamble scanning window to be greater than said maximum bidirectional propagation delay value of said first speech sphere;

d) if an access channel is sent from said specific mobile station in said border area, allowing both of said first and second signal processors to detect and demodulate said access channel synchronously, respectively, with said first and second EVEN SECOND clocks and measure first and second bidirectional propagation delay times with said specific mobile station, respectively;

e) allowing said first signal processor to assign a traffic channel synchronously with said first EVEN SECOND clock and transmit it to said specific mobile station;

f) if a reverse traffic channel is sent from said specific mobile station, allowing both of said first and second signal processors to detect and demodulate said reverse traffic channel synchronously, respectively, with said first and second EVEN SECOND clocks;

g) comparing said first and second bidirectional propagation delay times measured at said step d) with each other to determine which one of said first and second speech spheres is a near-by speech sphere; and

h) selecting and utilizing said reverse traffic channel demodulated by said first signal processor if said first speech sphere is determined to be the near-by speech sphere at said step g) and selecting and utilizing said reverse traffic channel demodulated by said second signal processor if said second speech sphere is determined to be the near-by speech sphere at said step g).

10. In a method for operating a CDMA base station which partitions a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the movement of a specific mobile station located in said first speech sphere to said second speech sphere, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) if an access channel is sent from said specific mobile station located in said first speech sphere, allowing said first signal processor to detect and demodulate said access channel synchronously with said first EVEN SECOND clock;

d) allowing said first signal processor to assign a forward traffic channel synchronously with said first EVEN SECOND clock and transmit it to said specific mobile station in said first speech sphere;

e) if a reverse traffic channel is sent from said specific mobile station in said first speech sphere, allowing said first signal processor to detect and demodulate said reverse traffic channel synchronously with said first EVEN SECOND clock;

f) allowing said first signal processor to measure a first bidirectional propagation delay time with said specific mobile station at an interval of predetermined time and compare the measured first bidirectional propagation delay time with a first threshold value;

g) allowing said first signal processor to repeatedly measure said first bidirectional propagation delay time if said first bidirectional propagation delay time is smaller than said first threshold value at said step f) and, if said first bidirectional propagation delay time is greater than or equal to said first threshold value at said step f), allowing said first signal processor to subtract said maximum bidirectional propagation delay value of said first speech sphere from said first bidirectional propagation delay time and set the subtracted result as a second bidirectional propagation delay time;

h) allowing said second signal processor to detect and demodulate said reverse traffic channel from said specific mobile station synchronously with said second bidirectional propagation delay time and assign a forward traffic channel ahead;

i) allowing said second signal processor to compare said second bidirectional propagation delay time with a second threshold value; and

j) if said second bidirectional propagation delay time is greater than or equal to said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said second signal processor and then transmitting said forward traffic channel assigned by said second signal processor to said specific mobile station.

11. The speech disable state solving method as set forth in claim 10, further comprising the steps of:

k) allowing said second signal processor to measure a third bidirectional propagation delay time with said specific mobile station, add said maximum bidirectional propagation delay value of said first speech sphere to the measured third bidirectional propagation delay time and set the added result as a fourth bidirectional propagation delay time;

l) allowing said second signal processor to compare said fourth bidirectional propagation delay time measured at said step k) with a third threshold value; and

m) returning to said step k) if said fourth bidirectional propagation delay time is smaller than said third threshold value at said step l) and stopping the demodulation operation of said first signal processor if said fourth bidirectional propagation delay time is greater than or equal to said third threshold value at said step l).

12. The speech disable state solving method as set forth in claim 10, further comprising the step of k), if said second bidirectional propagation delay time is smaller than said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said first signal processor, transmitting said forward traffic channel assigned by said first signal processor to said specific mobile station and then returning to said step f).

13. The speech disable state solving method as set forth in claim 10, wherein said first to third threshold values are defined as follows:

maximum bidirectional propagation delay value of first speech sphere<

first threshold value<

second threshold value<

third threshold value<

maximum bidirectional propagation delay value limited by modem ASIC.

14. In a method for operating a CDMA base station which partitions a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the movement of a specific mobile station located in said second speech sphere to said first speech sphere, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) if an access channel is sent from said specific mobile station located in said second speech sphere, allowing said second signal processor to detect and demodulate said access channel synchronously with said second EVEN SECOND clock;

d) allowing said second signal processor to assign a forward traffic channel ahead and transmit it to said specific mobile station in said second speech sphere;

e) if a reverse traffic channel is sent from said specific mobile station in said second speech sphere, allowing said second signal processor to detect and demodulate said reverse traffic channel synchronously with said second EVEN SECOND clock;

f) allowing said second signal processor to measure a first bidirectional propagation delay time with said specific mobile station at an interval of predetermined time, add said maximum bidirectional propagation delay value of said first speech sphere to the measured first bidirectional propagation delay time and set the added result as a second bidirectional propagation delay time;

g) allowing said second signal processor to compare said second bidirectional propagation delay time with a first threshold value;

h) returning to said f) if said second bidirectional propagation delay time is greater than said first threshold value at said step g) and, if said second bidirectional propagation delay time is smaller than or equal to said first threshold value at said step g), allowing said first signal processor to detect and demodulate said reverse traffic channel from said specific mobile station synchronously with said second bidirectional propagation delay time and to assign a forward traffic channel;

i) allowing said second signal processor to compare said second bidirectional propagation delay time with a second threshold value; and

j) if said second bidirectional propagation delay time is smaller than or equal to said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said first signal processor and transmitting said forward traffic channel assigned by said first signal processor to said specific mobile station.

15. The speech disable state solving method as set forth in claim 14, further comprising the steps of:

k) allowing said first signal processor to measure a third bidirectional propagation delay time with said specific mobile station and compare the measured third bidirectional propagation delay time with a third threshold value; and

l) allowing said first signal processor to repeatedly measure said third bidirectional propagation delay time if said third bidirectional propagation delay time is greater than said third threshold value at said step k) and stopping the demodulation operation of said second signal processor if said third bidirectional propagation delay time is smaller than or equal to said third threshold value at said step k).

16. The speech disable state solving method as set forth in claim 14, further comprising the step of k), if said second bidirectional propagation delay time is greater than said second threshold value at said step i), selecting and utilizing said reverse traffic channel demodulated by said second signal processor, transmitting said forward traffic channel assigned by said second signal processor to said specific mobile station and then returning to said step f).

17. The speech disable state solving method as set forth in claim 14, wherein said first to third threshold values are defined as follows:

first threshold value>

second threshold value>

third threshold value>

maximum bidirectional propagation delay value of first speech sphere.

18. In a method for operating a CDMA base station which partitions a speech radius wider than that limited in timing by a modem ASIC of said base station into first and second speech spheres by a predetermined unit below the maximum speech radius allowed by said base station modem ASIC to enlarge the limited speech radius, said base station having a first signal processor for processing forward link channels from said base station to mobile stations in said first and second speech spheres and reverse link channels from said mobile stations in said first speech sphere to said base station and a second signal processor for processing reverse link channels from said mobile stations in said second speech sphere to said base station, a method for solving a speech disable state based on the location of a specific mobile station in a border area between said first and second speech spheres, comprising the steps of:

a) allowing a clock generator to generate first and second EVEN SECOND clocks, said second EVEN SECOND clock being delayed from said first EVEN SECOND clock by the maximum bidirectional propagation delay value of said first speech sphere, and allowing said first and second signal processors to receive said first and second EVEN SECOND clocks from said clock generator, respectively;

b) allowing said first signal processor to assign pilot, synchronization and paging channels synchronously with said first EVEN SECOND clock and transmit them to all speech spheres covered by said base station;

c) allowing said first signal processor to set up the size of an access channel preamble scanning window to be greater than said maximum bidirectional propagation delay value of said first speech sphere;

d) if an access channel is sent from said specific mobile station in said border area, allowing both of said first and second signal processors to detect and demodulate said access channel synchronously, respectively, with said first and second EVEN SECOND clocks and measure first and second bidirectional propagation delay times with said specific mobile station, respectively;

e) allowing both of said first and second signal processors to assign forward traffic channels and transmit them to said specific mobile station;

f) if a reverse traffic channel is sent from said specific mobile station, allowing both of said first and second signal processors to detect and demodulate said reverse traffic channel synchronously, respectively, with said first and second EVEN SECOND clocks;

g) comparing said first and second bidirectional propagation delay times measured at said step d) with each other to determine which one of said first and second speech spheres is a near-by speech sphere; and

h) if said first speech sphere is determined to be the near-by speech sphere at said step g), selecting and utilizing said reverse traffic channel demodulated by said first signal processor and transmitting said forward traffic channel assigned by said first signal processor to said specific mobile station and, if said second speech sphere is determined to be the near-by speech sphere at said step g), selecting and utilizing said reverse traffic channel demodulated by said second signal processor and transmitting said forward traffic channel assigned by said second signal processor to said specific mobile station.