Frequency offset differential pulse position modulation
View Patent ↗The present invention provides such a need by utilizing a frequency offset differential pulse position modulation scheme to transmit data between computing devices within a wireless network system. The differential pulse position modulation component of the scheme enables the present invention to provide relative immunity to interference for the system. In particular, such immunity from interference is achieved by utilizing a blanking time between pulse positions, which is large enough to allow the interference between frequency offset—differential pulse position modulation pulses to subside. The frequency offset component of the scheme enables the system to utilize multiple frequency channels to enable the system to achieve higher data rates. In particular, by utilizing a time offset between the frequency channels, the blanking time can be reduced, thereby increasing the amount of data that can be transmitted with a set period of time.
1. An article comprising: one or more instructions stored on a computer readable medium that if executed by a computer result in transmitting a first pulse position modulation signal in a first frequency channel; transmitting a second pulse position modulation signal in a second frequency channel; and encoding data at least in part into the first pulse position modulation signal and/or the second pulse position modulation signal.
2. The article of claim 1 , wherein said encoding data comprises encoding the data at least in part into an amplitude component of the first pulse position modulation signal.
3. The article of claim 1 , wherein said encoding data comprises at least in part encoding the data by alternating between encoding the data into the first pulse position modulation signal and the second pulse position modulation signal.
4. The article of claim 1 , wherein said computer readable medium has stored thereon further instructions, that, if executed by the computer, result in encoding at least a portion of the data at least in part into a time difference between the first pulse position modulation signal and the second pulse position modulation signal.
5. An apparatus comprising:
means for identifying a first pulse transmission time in a first time window for a first bit sequence of a bit stream based on a first value of the first bit sequence;
means for transmitting a first signal at the identified first pulse transmission time using a first frequency;
means for identifying a second pulse transmission time in a second time window for a second bit sequence of the bit stream based on a second value of the second bit sequence; and
means for transmitting a second signal at the identified second pulse transmission time using a second frequency, wherein the first frequency is different than the second frequency, and further wherein the first time window and the second time window overlap at least partially in time.
6. The apparatus of claim 5 further comprising:
means for receiving the first signal;
means for receiving the second signal; and
means for decoding data at least in part from the first and the second signals.
7. The article of claim 5 , further comprising means for selecting an antenna of a plurality of antennas to transmit the first signal.
8. The article of claim 7 , wherein the antenna is selected based on a signal strength of the first signal.
9. The article of claim 5 , wherein the first bit sequence comprises a plurality of bits.
10. The article of claim 5 , wherein the second time window is offset from the first time window by a fixed amount of time.
11. The article of claim 5 , wherein a length in time of the first time window is based on a number of bits in the first bit sequence.
12. The article of claim 5 , wherein the first pulse transmission time is identified by selecting a counter value based on the first value of the first bit sequence.
13. The article of claim 12 , wherein the first signal is transmitted when the counter value is zero.
14. The article of claim 5 , further comprising means for identifying a third pulse transmission time in a third time window for a third bit sequence of the bit stream based on a third value of the third bit sequence; and
means for transmitting a third signal at the identified third pulse transmission time using a third frequency, wherein the third frequency is different than the first frequency and the second frequency, and further wherein the first time window, the second time window, and the third time window overlap at least partially in time.
15. An article comprising: one or more instructions stored on a computer readable medium that if executed by a computer result in encoding a first portion of data; transmitting the encoded first portion of data at least in part in a first pulse position modulation signal in a first frequency channel; encoding a second portion of data at least in part while transmitting the first portion of data; and transmitting the encoded second portion of data at least in part in a second pulse position modulation signal in a second frequency channel.
16. The article of claim 15 , wherein encoding the first portion of data comprises encoding the first portion of data at least in part into an amplitude component of the first pulse position modulation signal.
17. The article of claim 16 , wherein encoding the second portion of data further comprises encoding the second portion of data at least in part into an amplitude component of the second pulse position modulation signal.
18. The article of claim 15 , wherein said computer readable medium has stored thereon further instructions that, if executed by the computer, result in encoding a third portion of data at least in part into a time difference between the first pulse position modulation signal and the second pulse position modulation signal.