1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 3.00 out of 5)
Loading ... Loading ...
Print Print

TETRA Air interface specifications – Overview

by Krishna Sankar on February 2, 2010

TETRA (TErrestrial Trunked RAdio) is a wireless specification intended to be used by government agencies, public health services, rail transport, military etc. TETRA specification comes from ETSI (European Telecommunication Standards Institute). We plan to start a post series on the building blocks of TETRA physical layer and radio specifications and this is the first post towards that step.

Documents

a) All the standardization documents from ETSI are available online here

b) From the above list, the key document for us to study the physical layer and RF specification is
Doc. Nb. EN 300 392-2 Ver. 3.2.1, Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 2: Air Interface (AI). Ref. REN/TETRA-03152

Physical Layer Overview

TETRA specification allows for two modulation types

a) Phase Modulation

The overview of the building blocks in phase modulation is as shown below

Overview of TETRA phase modulation

Figure: Overview of TETRA phase modulation (reference Fig 4.1 ETSI EN 300 392-2 Ver 3.2.1)

For phase modulation, based on the data type, the following channel coding schemes are employed

a) Reed Muller (30,14) code or Block Code

b) Rate Compatible Punctured Convolutional code (RCPC)

c) Block Interleaver

d) Scrambler

e) Modulation of Differential Quarternary Phase Shift Keying ( DQPSK) or Differential 8PSK ( D8PSK)


TETRA QAM modulation overview

Figure: Overview of TETRA QAM modulation (reference Fig 4.2 ETSI EN 300 392-2 Ver 3.2.1)

For QAM modulation, based on the data type, the following channel coding schemes are employed

a)  Reed Muller (16,5) code or Block code

b) Parallel Concatenated Convolutional Code (PCCC)

c) Interleaver

d) Scrambler

e) Modulation of 4-QAM, 16-QAM or 64–QAM

In the upcoming posts in this series we will discuss each of these building blocks in more detail.

D id you like this article? Make sure that you do not miss a new article by subscribing to RSS feed OR subscribing to e-mail newsletter. Note: Subscribing via e-mail entitles you to download the free e-Book on BER of BPSK/QPSK/16QAM/16PSK in AWGN.

{ 4 comments… read them below or add one }

Major Lothrop March 13, 2012 at 11:48 am

Thank you so much for giving me an update on this matter on your website. Please understand that if a new post appears or in the event any variations occur on the current write-up, I would be considering reading more and focusing on how to make good using of those tactics you discuss. Thanks for your efforts and consideration of other individuals by making this web site available.

Reply

Jaroslav May 10, 2011 at 3:15 am

Anyone implemneted TETRA standard( stack/waveform generation) in MATLAB
and can share the code?

Reply

Krishna Sankar May 24, 2011 at 5:20 am

@Jaroslav: Sorry, I do not have it handy

Reply

Eric February 28, 2010 at 6:18 pm

I can’t wait !

Reply

Leave a Comment

{ 1 trackback }

Previous post:

Next post: