ETSI TR 103 053 V1.1.1 (2014-09)

Fixed Radio Systems; Parameters affecting the Signal-to-Noise Ratio (SNR) and the Receiver Signal Level (RSL) threshold in point-to-point receivers; Theory and practice

DTR/ATTM-04015

General Information

• Status: Published
• Publication Date: 04-Sep-2014
• Technical Committee: ATTM TM4 - Fixed Radio Systems
• Current Stage: 12 - Completion
• Due Date: 29-Sep-2014
• Completion Date: 05-Sep-2014

Standards Content (Sample)

ETSI TR 103 053 V1.1.1 (2014-09)






TECHNICAL REPORT
Fixed Radio Systems;
Parameters affecting the Signal-to-Noise Ratio (SNR)
and the Receiver Signal Level (RSL) threshold
in point-to-point receivers;
Theory and practice

�

---------------------- Page: 1 ----------------------
2 ETSI TR 103 053 V1.1.1 (2014-09)



Reference
DTR/ATTM-04015
Keywords
noise, point-to-point, receiver
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
http://portal.etsi.org/chaircor/ETSI_support.asp
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2014.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 ETSI TR 103 053 V1.1.1 (2014-09)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Definitions, symbols and abbreviations . 6
3.1 Definitions . 6
3.2 Symbols . 6
3.3 Abbreviations . 6
4 Proposed technical parameters . 7
4.1 Forward error correction code . 7
4.2 Noise figure and RX duplexer loss . 10
4.3 Channel Separation (ChS) . 11
4.4 Phase noise . 11
4.5 Non-linear distortion . 15
4.6 Internal distortion . 15
4.7 Industrial margin . 16
4.8 Evaluation of the RSL . 16
5 Conclusion . 17
Annex A: Illustration of Signal to Noise degradation . 18
Annex B: Evaluation of the RSL spreadsheet . 21
History . 22

ETSI

---------------------- Page: 3 ----------------------
4 ETSI TR 103 053 V1.1.1 (2014-09)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Access, Terminals, Transmission and
Multiplexing (ATTM).
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "may not", "need", "need not", "will",
"will not", "can" and "cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms
for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
Digital Fixed Radio Systems (DFRS) had been historically specified in a relatively large number of specific European
Norms produced by ETSI. These ENs were prepared separately and, even if the list of standardized parameters was
common to all these ENs, their specific values were defined on a case-by-case basis. The content of the old Point-to-
Point ENs was further transferred into the multipart standard EN 302 217 [i.4] while in a first time most of the
parameters values were kept unchanged.
As a consequence the RSL figures provided in earlier versions up to V1.4.1 of EN 302 217-2-2 [i.2] are an array of
values proposed at different times and corresponding to different technology situations.
ETSI

---------------------- Page: 4 ----------------------
5 ETSI TR 103 053 V1.1.1 (2014-09)
1 Scope
The present document provides guidance for the definition of a full set of rationalized RSL values based on the most
recent technological state-of-the-art and determined using a common set of rules for all P-P systems within the scope of
EN 302 217 [i.4].
As part of the rationalization effort of EN 302 217 [i.4], the present document proposes technical parameters to be used
as basis in the calculation of the RSL figures.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI EN 302 217-1: "Fixed Radio Systems; Characteristics and requirements for point-to-point
equipment and antennas; Part 1: Overview and system-independent common characteristics".
[i.2] ETSI EN 302 217-2-2: "Fixed Radio Systems; Characteristics and requirements for point-to-point
equipment and antennas; Part 2-2: Digital systems operating in frequency bands where frequency
co-ordination is applied; Harmonized EN covering the essential requirements of article 3.2 of the
R&TTE Directive".
[i.3] Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio
equipment and telecommunications terminal equipment and the mutual recognition of their
conformity (R&TTE Directive).
[i.4] ETSI EN 302 217 (all parts): "Fixed Radio Systems; Characteristics and requirements for point-to-
point equipment and antennas".
[i.5] IEEE 802.16: "IEEE Standard for Air Interface for Broadband Wireless Access Systems".
[i.6] Recommendation ITU-R F.1101: "Characteristics of digital fixed wireless systems below about
17 GHz".
ETSI

---------------------- Page: 5 ----------------------
6 ETSI TR 103 053 V1.1.1 (2014-09)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
air interface interoperability: requirement by which DFRS terminals from different manufacturer can be connected
inside the same radio systems
NOTE: It requires standardization of the physical radio layer (e.g. modulation format, digital codings,
synchronization procedures, etc.) and part or all of the higher network layers protocols.
digital fixed radio systems: comprise the whole family of Point-to-point (P-P), Point-to-multipoint (P-MP) and
Multipoint-to-multipoint (MP-MP) radio equipment (see note 2), which may be used in fixed locations as part of public
or private core or access networks (see note 3)
NOTE 1: It is equivalent to the ITU-R definition of Fixed Wireless Systems (FWS) and comprises Fixed Wireless
Access (FWA) systems and, in specific cases, their optional extension to Nomadic Wireless Access
(NWA).
NOTE 2: The two latter generically identified as Multipoint (MP) systems.
NOTE 3: Analogue systems are no longer implemented; therefore, for the purpose of the present document only
digital applications are identified as DFRS.
essential phenomenon: radio frequency phenomenon related to the essential requirements under article 3.2 of the
R&TTE Directive [i.3] that is capable of expression in terms of quantifiable technical parameters
harmonized radio frequency band: commonly referred to as a portion of the frequency spectrum that CEPT/ECC
(formerly CEPT/ERC) allocates to a specific service through a CEPT/ECC Decision (proper definition is currently
under study by CEPT/ERC)
NOTE: It should be noted that, presently, radio frequency bands allocated to Fixed Service are not harmonized.
3.2 Symbols
For the purposes of the present document, the following symbols apply:
dB deciBels
GHz GigaHertz
Hz Hertz
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AWGN Additive White Gaussian Noise
BER Bit Error Ratio
CRL Carrier Removal Loop
CS Channel Separation
DEG Signal Degradation
DFRS Digital Fixed Radio System
EVM Error Vector Magnitude
FEC Forward Error Correction Code
FSK Frequency Shift Keyed
GF Galois Field
NOTE: RS code is based on its properties.
rd
IM3 3 order Inter Modulation
IMD Inter Modulations Distortion
IPN Integrated Phase Noise
ITU-R International Telecommunication Union - Radiocommunications standardization sector
ETSI

---------------------- Page: 6 ----------------------
7 ETSI TR 103 053 V1.1.1 (2014-09)
LDPC Low Density Parity Checking Code
LNA Low Noise Amplifier
LO Local Oscillator
MLC Multi-Level Coding
N Degraded noise power
DEG
NEB Noise Equivalent Bandwidth
NF Noise Figure
PLL Phase Locked Loop
PN Phase Noise
PSK Phase Shift Keying
QAM Quadrature Amplitude Modulation
RF Radio Frequency
RRC Root Raised Cosine
NOTE: A common type of channel filter.
RS Reed-Solomon code
NOTE: A common type of forward error correction code.
RSL Receiver Signal Level
NOTE: Given at dBm of signal at the antenna port.
RX Receiver
S Power of a degraded signal
DEG
S Signal power without any source of degradation
ND
SNR Signal to Noise Ratio
TCM Trellis Coded Modulation
TX Transceiver
VCO Voltage Controlled Oscillator
4 Proposed technical parameters
The RSL (Received Signal Level) is defined for the following BER points:
-6
• RSL for BER ≤ 10
• -8
RSL for BER ≤ 10
• -10
RSL for BER ≤ 10
4.1 Forward error correction code
Modern P-P digital fixed radio systems use Forward Error Correction (FEC) Coding, also called Channel Coding, to
improve BER performance.
Many types of FECs are available in today's communication world. These codes, specifically when associated to an
iterative decoding process, offer unprecedent coding gain, thus enabling new communication schemes to operate closer
and closer to the Shannon bound.
The two main categories of FEC are block codes and convolutional codes. Coded modulation is a particular coding
scheme where the coding gain results from an expansion of the number of states of the modulation format for a given
spectral efficiency rather than by an increase of the transmitted bitrate.
The following coding schemes are currently implemented:
• Block codes, typically Reed-Solomon (RS) codes.
• Coded modulation: Several coded modulation schemes with very similar performance are described in the
literature, especially Multi-level coding (MLC) and Trellis Coded Modulation (TCM).
ETSI

---------------------- Page: 7 ----------------------
8 ETSI TR 103 053 V1.1.1 (2014-09)
• A combination of an outer code and an inner code, which provides increased BER performance. This
combination generally associates a RS code as outer code and a coded modulation scheme as inner code. The
benefit of this association is balanced by the higher latency of the transmission system, due to the need to
implement an interleaving matrix between the outer and inner codes.
• Turbo codes and/or Low Density Parity Checking (LDPC) codes which, being using iterative decoding
techniques, provide results close to the Shannon limit.
As an example, this clause presents the characteristics in terms of BER of a P-P equipment using two Reed-Solomon
codes, RS(204, 188) and RS(200, 190) respectively.
RS(204, 188), which is a Reed-Solomon code over GF(256), has been retained by several standardization bodies. This
code has approximately 8 % redundancy and typically corrects up to 8 errored bytes in every block of 204 bytes.
The code RS(204,188) is used in many applications such as DVB-S/T/C, IEEE 802.16 [i.5] and others.
A lower code rate (with approximately 5 % redundancy) is also considered, this code RS(200,190) typically corrects up
to 5 errored bytes in every block of 200 bytes.
The performance of RS(204, 188) and RS(200,190) are reported in figure 1 and figure 2 respectively.

NOTE: The spectral efficiency is the "net" one (i.e. divided by 204/188).

Figure 1: BER and modulation index as function of SNR for RS(188,204)
ETSI

---------------------- Page: 8 ----------------------
9 ETSI TR 103 053 V1.1.1 (2014-09)

NOTE: The spectral efficiency is the "net" one (i.e. divided by 200/190).

Figure 2: BER and modulation index as function of SNR for RS(190,200)
The Signal-to-Noise Ratio (SNR) for a given BER is a characteristic of the coding and modulation format. The
-6
theoretical values of SNR at a BER of 10 for coded and uncoded systems using modulation formats from 2 PSK to
1 024 QAM are provided in table 1.
-6
Table 1: SNR at BER of 10 for different modulation and coding formats
Modulation Uncoded (see note) Coded (RS200,190) Coded (RS204,188)
(dB) (dB) (dB)
2 PSK 10,5 7,5 6,8
4 QAM 13,5 10,5 9,8
8 PSK 18,8 15,5 14,8
16 QAM 20,5 17,2 16,5
32 QAM 23,5 20,4 19,7
64 QAM 26,5 23,4 22,7
128 QAM 29,5 26,3 25,6
256 QAM 32,5 29,3 28,6
512 QAM 35,5 32,1 31,4
1 024 QAM 38,7 34,8 33,9
NOTE: The values of SNR for uncoded systems from 2 PSK to 512 QAM are taken from
Recommendation ITU-R F.1101 [i.6].

Taking into account the proximity of these results a coding gain of 3 dB for all modulation formats has been assumed in
the calculations and will reflect "maximal values" of SNR for modern systems implementing coded modulations.
The theoretical SNR values at lower bit rates could also be determined the same way. With the RS error correction
-6 -10
code, the 10 /10 slope is of 1 dB or less.
Nevertheless, such a slope would not reflect properly actual conditions in digital fixed radio systems:
• Even at high C/IM3 ratio, the amount of degradation of different BER thresholds due to C/IM3 ratio is likely
not to be the same at different BERs.
• At very low BER, a number of other implementation factors (e.g. scrambling, mapping, clock imprecision,
uncoded bytes, etc.) give significant impact to actual SNR that can hardly be simulated.
ETSI

---------------------- Page: 9 ----------------------
10 ETSI TR 103 053 V1.1.1 (2014-09)
-6
Therefore, while simulations for BER 10 , where the thermal noise is the dominant factor, provide appropriate
calculation of the degradation, at lower BER a pragmatic approach has been adopted, using a predefined slope between
-6
RSL at a BER of 10 and RSL at lower BER.
-8 -10
and SNR at BER of 10
Table 2: Derivation of SNR at BER of 10
BER SNR "maximal"
-6
3 dB coding gain
10
-8 -6
10 SNR at BER of 10 + 1,5 dB
-10 -6
10 SNR at BER of 10 + 3 dB

4.2 Noise figure and RX duplexer loss
Noise figure and the RX duplexer losses are obviously contributing to the degradation of the sensitivity of the system;
they are necessary parameters for defining the RSL threshold.
In common practice, the "system
...