STANDARD:

STANAG 4539

Overview

STANAG 4539 defines the technical standards to enable interoperability of land, air and maritime narrowband HF radio modems. The standard describes the Serial Tone Mode (STM) providing data rates ranging from 75 to 9600 bps coded, and 12800 bps uncoded, in a 3 kHz channel.

Status

The STANAG 4539 (Edition 1) “Technical Standards for Non-Hopping HF Communications Waveforms” was released in Jun 2005.

Key Features

Very robust traffic waveformproviding a 75 bps autobaud data modem for conveying data traffic over severely degraded channels, as specified in STANAG 4415.
Low to medium data rate traffic waveforms providing autobaud data modem with data rates ranging from 150 to 2400 bps coded, as specified in MIL-STD-188-110 (Section 5.3).
High data rate traffic waveforms providing autobaud data modem with data rates ranging from 3200 to 9600 bps coded and 12800 bps uncoded. Specifically, Annex Bof the STANAG 4539 standard specifies the HF Data Modem Waveforms for data rates above 2400 bps.
Non-hopping TDMA traffic waveforms providing data modems for HF fixed frequency slotted TDMA operation. Specifically, Annex D of the STANAG 4539 standard specifies the modulation types and contents for three TDMA waveforms, namely WF1, WF2 and WF3.

Relevance

The single tone PSK waveforms are important for backwards interoperability with NATO BRASS systems used by Navies.

Serial Tone Mode (STM)

The table below summarises the complete STANAG 4539 waveform suite. Included in the table are the modulation, code rate and interleaver settings for each data rate. The STANAG 4539 waveform includes tone excision apability to supress narrowband interferers. The inclusion of tone excision improves the waveform resilience and performance in the presence of channel interference.

Waveform	Data Rate (bps)	Modulation Constellation	Coding Rate	Interleaver Settings	Tone Excision Capability
S 4539	75 C	Walsh	1/2	Z, S, L	YES
	150 C	BPSK	1/8		YES
	300 C	BPSK	1/4		YES
	600 C	BPSK	1/2		YES
	1200 C	QPSK	1/2		YES
	2400 C	8-PSK	1/2		YES
	2400 C VOICE	8-PSK	1/2	Z, S	YES
	3200 C	QPSK	3/4	US, VS, S, M, L, VL	NO
	4800 C	8-PSK	3/4	US, VS, S, M, L, VL	NO
	6400 C	16-QAM	3/4		NO
	8000 C	32-QAM	3/4		NO
	9600 C	64-QAM	3/4		NO
	12800 U	64-QAM	None	None	NO

Table 1: STANAG 4539 – STM Waveform Suite

The following tables give performance results for the RM modems for various data rates. The results were measured using an HF Channel Simulator.

An AWGN channel is representative of ground wave propagation, while the POOR channel represents skywave conditions. A RICEAN channel has a steady (specular) component and a fading component, thus representing a mixture of the ground and skywave propagation scenarios.

STANAG 4539
AWGN Channel (STANAG 4203 Filters included)
Data Rate [bps]	IB	SNR for BER=10^-5[dB in 3kHz]
Data Rate [bps]	IB	Mandatory Requirement	Design Objective	Measured
12800	N/A	28	–	25.7
9600	VL	22	20	19.5
8000	VL	19	17	16.4
6400	VL	16	14	13.7
4800	VL	14	12	11.2
3200	VL	9	7	6.6
RICEAN Channel (STANAG 4203 Filters included)
Data Rate [bps]	IB	SNR for BER=10^-5[dB in 3kHz]
Data Rate [bps]	IB	Mandatory Requirement	Design Objective	Measured
9600	VL	32	29	24.2
8000	VL	26	23	20.6
6400	VL	22	19	17.0
4800	VL	18	15	14.0
3200	VL	13	–	9.4

POOR Channel (STANAG 4203 Filters included)
Data Rate [bps]	IB	SNR for BER=10^-5[dB in 3kHz]
Data Rate [bps]	IB	Mandatory Requirement	Design Objective	Measured
9600	VL	32	29	27.6
8000	VL	28	25	23.5
6400	VL	24	–	20.8
4800	VL	21	18	17.0
3200	VL	15	–	12.6

Table 2: Performance: STANAG 4539