System and method for a differential pulse position modulation encoder and decoder
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsDaniel Collins, Glenn Shevach, Mark Blair
Life of this patent
Estimating the term…
Abstract
A system and method using Differential Pulse Position Modulation (DPPM) to encode digital data so that it can be transmitted using an infrared (IR) link. The digital data is then decoded upon receipt. This invention can be implemented in software and run on an FPGA (or the like) for prototyping and integration with existing designs. The encoding, decoding and sensitive timing are handled by dedicated hardware, which greatly increases the speed of these processes because it frees up the processor to accomplish other tasks.
Claims8
A method of encoding digital data comprising:
- receiving a first digital signal data from a source;
- storing the first digital signal data in a first latch;
- sending an instruction to the source that it is clear to send a second digital signal data;
- storing the first digital signal data in a first counter;
- activating a first delay timer trigger for a first delay timer and a, decrement timer trigger for a decrement timer simultaneously with storing the first digital signal data to the first counter;
- sending a signal to output a Differential Pulse Position Modulation (DPPM) pulse simultaneously with storing the first digital signal data to the first counter;
- connecting the decrement timer to the first counter;
- decrementing the first digital signal data stored in the first counter by one on each rising edge of a decrement timer pulse;
- checking the first counter to determine whether the first digital signal data is zero at each falling edge of the decrement time pulse;
- sending a signal to output a DPPM pulse when the first digital signal data is decremented to zero;
- and
- receiving a second digital signal data;
- and,
- repeating the above steps, except for sending a signal to output a DPPM pulse simultaneously with storing the first digital signal data to the counter, until the source sends an instruction that there is no more data to be transmitted.
Dependencies are inferred from the claim text.