An experimental fault resilient binary signal format for byte data

A digital transmission signal for packet data over any carrier capable of binary encoding. The signal is dense, self-synchronising and as error-resilient as reasonable.

The signal is also whitened for radio or electrical transmission.

All bytes from the original data are encoded as Fibonacci universal codes, between 2 and 14 bits long. This gives around 1.6 output samples per bit, with a total of around 2.2 samples per input bit for short messages when including framing and encoding.

Each frame starts with at least one instance of the 16 bit pattern 1010101010101011, and ends with the 16 bit pattern 0101010101010011. This gives a long sequence of alternating values to latch timing.

An extra 0 is added after each byte pattern

A stream reader can synchronise by looking for 0110, which should occur at the end of every 'byte'. The frame header gives both timing signal and start-of-frame in minimal space. The receiver can also expect to never see the sequence 111 or any more than 2 consecutive 1s

Any time the decoder sees an invalid sequence, it can mark the output as invalid. Extra 1 bits in the data are likely to trigger the inter-byte pattern 0110, and missing 1 bits can merge two byte patterns together; so the final length of damaged data is not likely to be the same as the input.

The resulting signal is highly patterned. 1 states are always either 1 or 2 samples long, 0 states are between 1 and 4 samples long.

The samples are arrange to give the shortest sequences to 0x00 bytes, 0xFF bytes and English text in ASCII or UTF8 encoding. In these cases, the encoded data may be slightly shorter than the input.

In the average case for random data, expect output that is 140% of the input length. Worst case is 15 bits out for each 8 bits in, plus 32 bits for header and footer.

The transcoder does not buffer more than a few bytes of input or output, and should be safe to run against streams of unbounded length.