Scheduling techniques for a packet-access network

• US 20040066766A1
• Filed: 10/03/2002
• Published: 04/08/2004
• Est. Priority Date: 10/03/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malladi, Durga P., Shiu, Da-shan
• Granted Patent: US 7,653,028 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference

Abstract

Multiple access interference may be substantially removed by introducing a near-far situation in which a near mobile and a far mobile (“near” and “far” based on signal strength) are selected, resources allocated among these and other mobiles, and the data is packetized for transmission during a transmission interval such that the data intended for the far mobile is transmitted along with the data intended for the near mobile. Forward link signals are then appropriately scheduled. Signals intended for the far mobile and the near mobile are decoded from the composite signal received at the near mobile. The signal intended for the far mobile is then removed from the composite signal received at the near mobile.

Claims

1. A method for substantially reducing multiple access interference in a communication network, the method comprising:

configuring a base station transceiver for a near-far situation in a cell of the network;

decoding a signal intended for a far mobile and a signal intended for a near mobile from a composite signal received at the near mobile; and

substantially removing the signal intended for the far mobile from the composite signal received at the near mobile.

2. The method of claim 1, wherein configuring a near-far situation includes:

selecting a near mobile and a far mobile;

allocating resources among the near mobile, the far mobile, and other mobiles; and

packetizing data for transmission during a transmission interval such that the signal intended for the far mobile is transmitted along with the signal intended for the near mobile.

3. The method of claim 2, further comprising:

receiving control information relating to the signal intended for the far mobile.

4. The method of claim 3, wherein the control information includes Walsh codes.

5. The method of claim 3, wherein the control information includes utilized modulation.

6. The method of claim 3, further comprising:

decoding the signal intended for the far mobile using the received control information before decoding the signal intended for the near mobile.

7. The method of claim 1, wherein decoding a signal intended for a far mobile includes decoding signals intended for a plurality of selected far mobiles.

8. The method of claim 7, wherein substantially removing includes removing the signals intended for the plurality of selected far mobiles from the composite signal received at the near mobile.

9. The method of claim 1, wherein introducing includes appropriately allocating resources for signals transmitted from a base station to mobiles.

10. The method of claim 1, wherein decoding includes monitoring forward packet data control channels.

11. The method of claim 10, wherein decoding includes examining the packet data control channels.

12. The method of claim 11, wherein examining includes checking an outer cyclic redundancy code (CRC) field.

13. The method of claim 12, wherein examining includes checking an inner CRC field, if the outer CRC field passes.

14. The method of claim 13, wherein decoding includes obtaining code tree information for the far mobile if the outer CRC passes but the inner CRC does not match that of the near mobile.

15. The method of claim 14, wherein the code tree information includes Walsh codes for the far mobile.

16. The method of claim 15, wherein decoding includes decoding packets intended for the far mobile using the obtained Walsh codes for the far mobile.

17. The method of claim 13, wherein decoding includes obtaining code tree information for the near mobile if the outer CRC passes and the inner CRC matches that of the near mobile.

18. The method of claim 17, wherein the code tree information includes Walsh codes for the near mobile.

19. The method of claim 18, wherein decoding includes decoding packets intended for the near mobile using the obtained Walsh codes for the near mobile.

20. A method for substantially reducing intra-cell interference in a communications network, comprising:

selecting a near mobile;

selecting a far mobile;

transmitting a composite signal from a base station to the near mobile and the far mobile;

decoding a signal intended for the far mobile from the composite signal received at the near mobile; and

substantially removing the signal intended for the far mobile from the composite signal received at the near mobile.

21. The method of claim 20, wherein the near mobile is relatively closer to the base station than the far mobile.

22. The method of claim 20, wherein the near mobile has relatively higher signal-to-interference-and-noise ratio (SINR) than the far mobile.

23. The method of claim 20, wherein the transmitting signal from a base station includes transmitting the signals intended for the near and the far mobiles.

24. A method for a base station to substantially reduce multiple access interference, the method comprising:

configuring a transceiver for a near-far situation including selecting a near mobile and a far mobile, allocating resources among the near mobile, the far mobile, and other mobiles, and packetizing data for transmission during a transmission interval into forward-link signals such that a signal intended for the far mobile is transmitted along with a signal intended for the near mobile; and

scheduling transmission of the appropriately-powered forward link signal to the mobiles.

25. A method for a mobile to substantially reduce multiple access interference, the method comprising:

receiving an appropriately-powered forward link composite signal;

decoding a signal intended for a far mobile and a signal intended for a near mobile from the composite signal received at a near mobile; and

substantially removing the signal intended for the far mobile from the composite signal received at the near mobile

26. A base station apparatus, comprising:

a transceiver configured to receive reverse link signals that have been transmitted from a plurality of mobiles, and to transmit appropriately-powered forward link signals to the mobiles;

a digital signal processor configured to demodulate and decode reverse link signals, and to modulate and encode forward link signals; and

a general purpose processor configured to determine an amount of power that should be allocated to each forward link signal, the general purpose processor including a scheduler that configures the transceiver for a near-far situation and schedules transmission of appropriately-powered forward link signals to the mobiles.

27. The base station apparatus of claim 26, wherein the scheduler includes:

a selector configured to select a near mobile and a far mobile;

a resource allocation element that allocates resources among the near mobile, the far mobile, and other mobiles; and

a data packetizer configured to packetize data for transmission during a transmission interval such that the data intended for the far mobile is transmitted along with the data intended for the near mobile.

28. A mobile apparatus, comprising:

a transceiver configured to receive forward link signals that have been transmitted from a base station apparatus, and to transmit appropriately-powered reverse link signals to the base station apparatus;

a digital signal processor configured to demodulate and decode forward link signals, and to modulate and encode reverse link signals; and

a general purpose processor configured to determine from the received forward link signals, signal intended for at least one far mobile apparatus and signal intended for a near mobile apparatus, the general purpose processor operating to substantially remove the signal intended for at least one far mobile from the forward link signals received at the near mobile apparatus.

29. The mobile apparatus of claim 28, further comprising:

a decoder for decoding signal intended for at least one far mobile apparatus.

30. The mobile apparatus of claim 29, wherein the decoder uses Walsh codes to decode the signal intended for at least one far mobile apparatus.

31. The mobile apparatus of claim 28, wherein the digital signal processor includes verifying elements configured to examine a forward link packet data channel packet by checking outer and the inner CRC fields.