Olivia Modes

Olivia 8/500 Spectrum Sound	Olivia 16/500 Spectrum Sound

Olivia 32/1000 Spectrum Sound

all signals shown in x1 waterfall mode, tick marks at 100 Hz intervals, waterfall palette is "blue-2"

General Description

Olivia is a family of MFSK modes with a high redundancy Forward Error Correction system similar to MT63. The family is very large, with 40 or more different options, which can make it very difficult to work out which is which. The mode works well on poor HF paths and has good sensitivity, and is best used for fixed skeds.

The most widely used versions have a symbol rate of 31.25 baud. The typing speed is varied by changing the number of tones used, but can also be changed by change of baud rate. RTTYM and Contestia are variants of Olivia. The MFSK is constant phase, and the transmission constant amplitude, so transmitter linearity is inimportant. The modes are moderately tolerant of mis-tuning. The typing rate is very modest, given the high bandwidth used.

The mode was designed by Pawel SP9VRC.

Protocol

These are unconnected, manually controlled message asynchronous symbol synchronous simplex chat modes, with full-time Forward Error Correction. The tones are spaced the same as the baud rate, for example 31.25Hz for the 31.25 baud modes. The default mode has 32 tones and is 1kHz wide.

Coding and Character Set

The ASCII-128 user interface is mapped to a block of sequential MFSK tones via a Walsh-Hadamard function (rate 7/64). Tones are deployed via a gray coder.

There are three popular modes, which have 8-FSK, 16-FSK and 32-FSK, thus having three, four or five bits per symbol. The modes have two serious shortcomings - excessive bandwidth combined with slow typing rate, and excessive latency (delay between overs).

Operating Parameters

Mode	Symbol Rate	Typing Speed¹	Lowest S/N	Duty Cycle²	Modulation	Bandwidth³	ITU Designation⁴
4-250	62.5 baud	~ 20 wpm	-12 dB	100%	4-FSK	250 Hz	250HF1B
8-250	31.25 baud	~ 15 wpm	-14 dB	100%	8-FSK	250 Hz	250HF1B
4-500	125 baud	~ 40 wpm	-10 dB	100%	4-FSK	500 Hz	500HF1B
8-500	62.5 baud	~ 30 wpm	-11 dB	100%	8-FSK	500 Hz	500HF1B
16-500	31.25 baud	~ 20 wpm	-13 dB	100%	16-FSK	500 Hz	500HF1B
8-1000	125 baud	~ 58 wpm	- 7 dB	100%	8-FSK	1000 Hz	1K00F1B
16-1000	62.5 baud	~ 40 wpm	-10 dB	100%	16-FSK	1000 Hz	1K00F1B
32-1000⁵	31.25 baud	~ 24 wpm	-12 dB	100%	32-FSK	1000 Hz	1K00F1B

Notes:
1. WPM is based on an average 5 characters per word, plus word space.
2. Transmitter average power output relative to a constant carrier of the same PEP value.
3. This is the "Necessary Bandwidth" as defined by the ITU.
4. A summary of the ITU Designation system can be found at http://en.wikipedia.org/wiki/Types_of_radio_emissions