jackokring / dcsspec

DCS squelch and data. Generic Android play-about.

DCSSpec

DCS squelch is a system using a 134.3 baud 23 bit Golay code. This project is to adapt this to a code for data transmission. The basic mode has 63 characters and 20 control codes. A more advanced block mode uses a form of base 64 coding to send UTF-8.

The data rate becomes 5.839 chars per second. Or slower with repeats. It does however occupy sub-bass and is recoverable from a low bandwidth signal. 67.15Hz is the maximum frequency needed, so the bandwidth is low and maybe inserted into guard bands in a spectrum for example, or sent over a PA system at a venue instead of visual QR codes.

There is enough code space to extend the coding, and all but 2 of the 177 codes maybe used. The current version 1 control codes include both channel control and optional space and colour locatives.

Any undefined code translates to the code UN to indicate non synchronisation. The 2 unusable codes are indicated by NOI as they are not phase invariant. They can be used to detect signal polarity and hence phase.

FM Bandwidth

Assuming a regular 15% deviation, in a channel for under 2.5kHz, or 5 DCS channels per VHF channel, the modulation index is very high. This has a very good signal to noise. Along with repeats of selective codes and overall repeat rstes controlling an intrinsic doubling of codes and halving of character rates, long distance on low power should be possible.

Laters

The app is being developed. My PC died. Other things todo and respect to the number 1 of W+/W- oscillation hybrid boson with an asymmetric mass and so an offset centre of null charge and such plus radiative corriolis emission to drift. Also my 13D theory has priority of thought for me. Flat gravity as a quantum intensity of noise conduction is no joke, as is not flat (or black possibly) electromagnetism.

• AGC avoid by -5, -2.5, 0, +2.5, +5 impulse within band max amplitude control.
• 3/5 pole LPF
• Non linear SN ratio increase filter.
• Band 3rd SSB devode by algorithm of amplitude inverse.
• Through zero FM encode and decode.
• Harmonic note up/down ring buffer split with post filter.
• Integral estimator noise reduction.
• Data compression collection.
• Messaging and spacetime locatives.
• DSA signed UTF-8 packets.
• Topological tree chain history.
• API lingo loader adapter for feeds.
• Bluetooth event ping closer nav proxy.

Under Construction