UPLINK TRANSMITTER IN A RANDOM PHASE MULTIPLE ACCESS COMMUNICATION SYSTEM

• US 20090238201A1
• Filed: 08/11/2008
• Published: 09/24/2009
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Ingenu Inc.
• Original Assignee: On-Ramp Wireless Incorporated
• Inventors: Myers, Theodore J.
• Granted Patent: US 7,593,383 B1
• Time in Patent Office: Days
• US Class Current: 370/442
• CPC Class Codes: H03J 7/02 Automatic frequency control H03J7/18 takes precedence
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70752 Partial correlation
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/0074 Code shifting or hopping
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 7/0004 Initialisation of the receiver H04L7/0075 and H04L7/10 take precedence

Abstract

A method for communicating through a multiple access communication interface includes receiving a first signal from a first tag, where the first signal is spread using a predetermined pseudo-noise (PN) code, and further where the first signal includes first payload data. A second signal is received from a second tag. The second signal is spread using the predetermined PN code, and the second signal includes second payload data. The first payload data from the first signal is identified at least in part with a PN array despreader. The second payload data from the second signal is also identified at least in part with the PN array despreader.

Claims

1. A method for communicating information to an access point, the method comprising:

generating a data stream at a processor;

spreading the data stream with a common pseudo-noise (PN) code, wherein the common PN code is used by a plurality of tags in communication with the access point;

applying a frequency offset to the data stream based at least in part on a timing of the access point; and

transmitting the data stream with a randomly selected timing offset.

2. The method of claim 1, wherein the common PN code comprises a gold code.

3. The method of claim 1, further comprising receiving an acknowledgement, wherein the acknowledgement indicates that a transmission of the data stream is successful.

4. The method of claim 1, further comprising re-transmitting the data stream with a second randomly selected timing offset if an acknowledgement is not received within a predetermined time period.

5. The method of claim 1, wherein the data stream is spread with a spreading factor of 64, 128, 256, 512, 1024, 2048, 4096, or 8192.

6. The method of claim 1, wherein the data stream is transmitted in a randomly selected sub-slot of a transmit slot.

7. The method of claim 1, wherein the randomly selected timing offset is between zero and a spreading factor minus one.

8. A transmit apparatus for communicating information to an access point, the transmit apparatus comprising:

a pseudo-noise (PN) spreader configured to receive a data stream and spread the data stream with a common PN code, wherein the common PN code is used by a plurality of tags in communication with the access point;

a frequency control rotator in communication with the PN spreader and configured to apply a frequency offset to the data stream based at least in part on a timing of the access point;

a delay module in communication with the frequency control rotator and configured to generate a randomly selected timing offset for the data stream; and

a transmitter configured to transmit the data stream with the randomly selected timing offset.

9. The transmit apparatus of claim 8, wherein the common PN code comprises a gold code.

10. The transmit apparatus of claim 8, further comprising an encoder configured to encode the data stream.

11. The transmit apparatus of claim 8, wherein the transmitter is further configured to re-transmit the data stream with a second randomly selected timing offset if an acknowledgement is not received within a predetermined time period.

12. The transmit apparatus of claim 8, wherein the data stream is spread with a spreading factor of 64, 128, 256, 512, 1024, 2048, 4096, or 8192.

13. The transmit apparatus of claim 8, wherein the transmitter is further configured to transmit the data stream in a randomly selected sub-slot of a transmit slot.

14. The transmit apparatus of claim 8, wherein the randomly selected timing offset is between zero and a spreading factor minus one.

15. A tag for communicating information to an access point, wherein the tag comprises:

a transmit apparatus comprising

a pseudo-noise (PN) spreader configured to receive a data stream and spread the data stream with a common PN code, wherein the common PN code is used by a plurality of tags in communication with the access point;

a frequency control rotator in communication with the PN spreader and configured to apply a frequency offset to the data stream based at least in part on a timing of the access point;

a delay module in communication with the frequency control rotator and configured to generate a randomly selected timing offset for the data stream; and

a transmitter configured to transmit the data stream with the randomly selected timing offset;

a processor in communication with the transmit apparatus, wherein the processor is configured to execute operations performed by the transmit apparatus; and

a receiver in communication with the processor.

16. The tag of claim 15, wherein the receiver is configured to receive an acknowledgement, and further wherein the acknowledgement indicates that a transmission of the data stream is successful.

17. The tag of claim 16, wherein the transmitter is further configured to re-transmit the data stream with a second randomly selected timing offset if the acknowledgement is not received within a predetermined time period.

18. The tag of claim 15, wherein the data stream is spread with a spreading factor of 64, 128, 256, 512, 1024, 2048, 4096, or 8192.

19. The tag of claim 15, wherein the transmitter is further configured to transmit the data stream in a randomly selected sub-slot of a transmit slot.

20. The tag of claim 15, wherein the randomly selected timing offset is between zero and a spreading factor minus one.