EFFICIENT PAGING IN A WIRELESS COMMUNICATION SYSTEM

• US 20100178942A1
• Filed: 03/23/2010
• Published: 07/15/2010
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Rangan, Sundeep, Hande, Prashanth
• Granted Patent: US 8,670,789 B2
• Time in Patent Office: Days
• US Class Current: 455/458
• CPC Class Codes: H04W 68/025 Indirect paging
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus for efficient two-stage paging wireless communications systems are described. Wireless terminals are assigned to paging groups. A few first paging message information bits are modulated (using non-coherent modulation) into a first paging signal and communicated from a base station to wireless terminals. WTs wake-up, receive the first paging signal and quickly ascertain whether its paging group should expect a second paging signal, if so, the WT is operated to receive the second paging signal; otherwise, the WT goes back to sleep conserving power. The base station modulates (using coherent modulation) a number of second message information bits into a second paging signal and transmits the signal to WTs. From the information in first and second paging signals, a WT can determine that it is the paged WT and process the paging instructions. The intended paged WT can transmit an acknowledgement signal on a dedicated uplink resource.

Claims

1. A method of paging a wireless terminal, the method comprising:

modulating a first number of bits of information to generate a first paging signal indicating if there is a paging message for at least one wireless terminal in a first group of wireless terminals, said first group being one of a plurality of wireless terminal groups;

modulating a second number of bits of information to generate a second paging signal, said second paging signal including, when there is a paging message, information to identify an individual wireless terminal in said first group to which the paging message is directed, said second paging signal communicating with said information at least a portion of said paging message;

transmitting said first paging signal; and

transmitting said second paging signal.

2. The method of claim 1, wherein modulating a first number of bits of information includes modulating multiple individual bits of information, some of said individual bits corresponding to different groups of wireless terminals, an individual bit corresponding to a group of wireless terminals indicating if there is a paging message for at least one wireless terminal in the group of wireless terminals to which the individual bit corresponds.

3. The method of claim 2, wherein said second paging signal is a second type paging signal, the method further comprising:

generating another second type paging signal corresponding to said first paging signal, said another second type paging signal communicating at least a portion of a second paging message, said second paging message being for a wireless terminal in a second wireless terminal group which is different from said first wireless terminal group; and

transmitting the another second type paging signal.

4. The method of claim 3, wherein transmitting said second paging signal is performed at a first fixed time offset from the time at which said first paging signal is transmitted;

and

wherein transmitting said another second type paging signal is performed at a second fixed time offset from the time at which said first paging signal is transmitted.

5. The method of claim 1, wherein transmitting said second paging signal includes transmitting said second paging signal in one of a plurality of different paging signal time slots corresponding to said first paging signal, the time slot in which said second paging signal is transmitted being determined based on which wireless terminal in the first group of wireless terminals said second paging message is directed.

6. The paging method of claim 5,

wherein modulating said first number of bits is performed using a first type of modulation;

and

wherein modulating the second number of bits is performed using a second type of modulation which is different from said first type of modulation, said second type of modulation requiring use of communications channel information to demodulate the information modulated with said second type of modulation.

7. The method of claim 6, wherein said non-coherent modulation type is one of on/off modulation, orthogonal modulation or differential modulation;

and

wherein said second type of modulation is one of quadrature phase shift keying or quadrature amplitude modulation.

8. The method of claim 1, wherein information included in said first paging message in combination with said sufficient information to indentify individual wireless terminals included in said second paging message uniquely identifies a wireless terminal in said system.

9. A base station for communicating with wireless terminals, said base station including:

first paging signal generation means for periodically generating paging signals of a first type, said paging signals of a first type indicating whether a paging message will be transmitted to at least one wireless terminal in a first group of wireless terminals, said first group being one of a plurality of wireless terminal groups, said first group including multiple wireless terminals;

second paging signal generation means for generating a paging signal of a second type, said paging signal of a second type including information to identify an individual wireless terminal in said first group to which the paging message is directed, said second paging signal communicating with said information at least a portion of said paging message; and

means for transmitting said first and second type paging signals.

10. The base station of claim 9,

wherein said first signal generation means includes means for modulating multiple individual bits of information, some of said individual bits corresponding to different groups of wireless terminals, an individual bit corresponding to a group of wireless terminals indicating if there is a paging message for at least one wireless terminal in the group of wireless terminals to which the individual bit corresponds

11. The base station of claim 9, further comprising:

a transmission timing means to control transmission of said second paging signal at a first fixed time offset from the time at which said first paging signal is transmitted and to control transmission of another second type paging signal at a second fixed time offset from the time at which said first paging signal is transmitted.

12. The base station of claim 9, further comprising:

signaling means for controlling said means for transmitting to transmit said second paging signal in one of a plurality of different paging signal time slots corresponding to said first paging signal, the particular time slot in which said second paging signal is transmitted being determined based on which wireless terminal in the first group of wireless terminals said second paging message is directed.

13. A base station for communicating with wireless terminals, said base station including:

a first paging signal generation module for periodically generating paging signals of a first type, said paging signals of a first type indicating whether a paging message will be transmitted to at least one wireless terminal in a first group of wireless terminals, said first group being one of a plurality of wireless terminal groups, said first group including multiple wireless terminals;

a second paging signal generation module for generating a paging signal of a second type, said paging signal of a second type including sufficient information to identify an individual wireless terminal in said first group to which the paging message is directed, said second paging signal communicating with said information at least a portion of said paging message; and

a transmitter for transmitting said first and second type paging signals.

14. The base station of claim 13,

wherein said first signal generation module includes a modulation module for modulating multiple individual bits of information, some of said individual bits corresponding to different groups of wireless terminals, an individual bit corresponding to a group of wireless terminals indicating if there is a paging message for at least one wireless terminal in the group of wireless terminals to which the individual bit corresponds.

15. The base station of claim 13, further comprising:

a transmission timing module to control transmission of said second paging signal at a first fixed time offset from the time at which said first paging signal is transmitted and to control transmission of another second type paging signal at a second fixed time offset from the time at which said first paging signal is transmitted.

16. The base station of claim 13, further comprising:

a signaling module for controlling said transmitter to transmit said second paging signal in one of a plurality of different paging signal time slots corresponding to said first paging signal, the particular time slot in which said second paging signal is transmitted being determined based on which wireless terminal in the first group of wireless terminals said second paging message is directed.

17. A computer readable medium including machine executable instruction for use in a base station that communicates with wireless terminals, said computer readable medium comprising:

instructions for causing the base station to modulate a first number of bits of information to generate a first paging signal indicating if there is a paging message for at least one wireless terminal in a first group of wireless terminals, said first group being one of a plurality of wireless terminal groups said first group including multiple wireless terminals;

instructions for causing the base station to modulate a second number of bits of information to generate a second paging signal, said second paging signal including, when there is a paging message, sufficient information to identify an individual wireless terminal in said first group to which the paging message is directed, said second paging signal communicating with said information at least a portion of said paging;

instructions for causing the base station to transmit said first paging signal; and

instructions for causing the base station to transmit said second paging signal.

18. The computer readable medium of claim 17, wherein modulating a first number of bits of information includes modulating multiple individual bits of information, some of said individual bits corresponding to different groups of wireless terminals, an individual bit corresponding to a group of wireless terminals indicating if there is a paging message for at least one wireless terminal in the group of wireless terminals to which the individual bit corresponds.

19. The computer readable medium of claim 17, wherein said second paging signal is a second type paging signal, the method further comprising:

generating another second type paging signal corresponding to said first paging signal, said another second type paging signal communicating at least a portion of a second paging message, said second paging message being for a wireless terminal in a second wireless terminal group which is different from said first wireless terminal group; and

transmitting the another second type paging signal.

20. The computer readable medium of claim 19, wherein transmitting said second paging signal is performed at a first fixed time offset from the time at which said first paging signal is transmitted;

and

wherein transmitting said another second type paging signal is performed at a second fixed time offset from the time at which said first paging signal is transmitted.