Method and system for uplink communication
A method for conserving bandwidth in a communication system includes spreading a data frame using a first pseudo-noise (PN) spreader. A broadcast frame is spread using a second PN spreader. A complex data stream having a first component and a second component is generated. The data frame is assigned to the first component and the broadcast frame is assigned to the second component. The complex data stream is transmitted to a tag.
1. A method for modulating a signal in a communication system, the method comprising:
spreading a data frame with a pseudorandom noise code at a transmitter to a spreading factor;
generating a data stream comprising a first component, wherein the data frame is assigned to the first component;
transmitting the data stream at a time wherein the time is determined in part from a start slot time plus a random chip delay while a second transmitter transmits at a second time a second data stream comprising a second data frame spread with the pseudorandom noise code to a second spreading factor wherein the second time is determined in part from the start slot time such that both the data stream and the second data stream are received.
2. The method of claim 1 , wherein the data stream is transmitted at a power level such that the data stream is received at a predetermined power level.
3. The method of claim 2 , wherein the power level is determined in part from a measured power level resulting from a measurement of a previously received transmission.
4. The method of claim 1 , further comprising attempting to receive an acknowledgement message at a receiver for a period of time after transmitting the data stream; and transmitting the data stream again if the acknowledgement message is not received within the period of time.
5. The method of claim 4 , wherein the acknowledgement message is spread using a second pseudorandom noise code.
6. The method of claim 1 , wherein the time is determined in part from a measurement of a previously received transmission.
7. The method of claim 1 , wherein the spreading factor is based at least in part on a quality of a previously received transmission.
8. The method of claim 7 , wherein the spreading factor is reduced if the quality of the previously received transmission satisfies a quality threshold such that a transmission time is minimized.
9. The method of claim 1 , wherein the data stream is transmitted on a frequency that is determined in part from a measurement of a previously received transmission.
10. A node comprising:
a processor configured to
spread a data frame with a pseudorandom noise code to a spreading factor;
generate a data stream comprising a first component, wherein the data frame is assigned to the first component; and
a transmitter operatively coupled to the processor and configured to transmit the data stream at a time wherein the time is determined in part from a start slot time plus a random chip delay while a second transmitter transmits at a second time a second data stream comprising a second data frame spread with the pseudorandom noise code to a second spreading factor wherein the second time is determined in part from the start slot time such that both the data stream and the second data stream are received.
11. The node of claim 10 , wherein the data stream is transmitted at a power level such that the data stream is received at a predetermined power level.
12. The node of claim 10 , wherein the spreading factor is based at least in part on a quality of a previously received transmission.
13. The node of claim 12 , wherein the spreading factor is reduced if the quality of the previously received transmission satisfies a quality threshold such that a transmission time is minimized.
14. The node of claim 10 , wherein the data stream is transmitted on a frequency that is determined in part from a measurement of a previously received transmission.
15. The node of claim 10 , wherein the time is determined in part from a measurement of a previously received transmission.
16. A computer-readable medium having computer-readable instructions stored thereon that, if executed by an access point, cause the access point to:
spread a data frame with a pseudorandom noise code to a spreading factor;
generate a data stream comprising a first component, wherein the data frame is assigned to the first component; and
transmit the data stream at a time wherein the time is determined in part from a start slot time plus a random chip delay while a second transmitter transmits a second data stream at a second time comprising a second data frame spread with the pseudorandom noise code to a second spreading factor wherein the second time is determined in part from the start slot time such that both the data stream and the second data stream are received.
17. The computer readable medium of claim 16 , wherein the data stream is transmitted at a power level such that the data stream is received at a predetermined power level.
18. The computer readable medium of claim 16 , wherein the spreading factor is based at least in part on a quality of a previously received transmission.
19. The computer readable medium of claim 18 , further comprising using a reduced spreading factor if the quality of the previously received transmission satisfies a quality threshold such that a transmission time is minimized.
20. The computer readable medium of claim 16 , wherein the data stream is transmitted on a frequency that is determined in part from a measurement of a previously received transmission.