23-04-19

Software Defined RadioSoftware Defined Radio

Activities within Europe in the European Commission’s TCAM

Committee and ETSI

1 GSC-9, Seoul

SOURCE: ETSI – ERM-TG#32

TITLE: Software Defined Radio

AGENDA ITEM: GRSC#2 Item 5

CONTACT: Phillipe Mege (philippe.mege@EADS-TELECOM.COM)

GSC9/GRSC_013

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The European Commission's TCAM The European Commission's TCAM Committee (1)Committee (1)

The Commission’s TCAM Committee is responsible for the regulatory environment created by the

R&TTE Directive• TCAM established a specialist ad hoc group to consider how

Software Defined Radio (SDR) products should be handled under the R&TTE Directive

• The ad hoc group produced a questionnaire “On the Impact of SDR on the R&TTE Directive”

• The aim of this consultation was to obtain comments from interested parties on a variety of issues relating to Software

Defined Radio• The questionnaire was published on the official European

Commission Web Pages last autumn

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The European Commission's TCAM The European Commission's TCAM Committee (2)Committee (2)

The Questionnaire covered four areas:

1. Questions related to when SDR equipment is likely to

appear on the market at the earliest (Q1, Q2)

2. Questions related to what SDR is likely to change in

the applicability of R&TTE (Q3 – Q9)

3. Questions related to possible changes in the R&TTE

Directive (Q10, Q11)

4. Standardisation (Q12 – Q13)

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The European Commission's TCAM The European Commission's TCAM Committee (3)Committee (3)

General Summary of the Answers to the Questionnaire:

• Under the “New approach guide” the product is considered a

new product if the software effects the essential requirements

• The provisions of R&TTE Directive are adequate as it requires

an entity (manufacturer) to take responsibility for the placing of

product on the market

• For the Software provider the same requirements should apply

as to hardware manufacture concerning the R&TTE-Directive

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ETSI ActivitiesETSI Activities

Software Defined Radio

ETSI activities centre around Task Group#32 of TC-ERM (EMC and Radio Spectrum Matters)

Link and impact to coexistence standards, methods of measurements and limits

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What is What is Software Software DefinedDefined Radio Radio ? ?

• Objective: Give more flexibility on Radio Front-End– For:

• Using the same Hardware Platform for different systems– Different standards

– Different frequency bands and frequency bandwidths

• Providing more easily interoperability• Downloading the air interface through the air for automatic

reconfiguration– By:

• Transferring the maximum of radio functions from analogue to digital– Sharing the radio function between analogue and digital

• Digitising at high sampling rate as close as possible to the antenna– instead of classically sampling at moderate rate in Intermediate

Frequency or in Baseband

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Classical Heterodyne architecture Classical Heterodyne architecture (Receiver chain)(Receiver chain)

HFFrontend

1st mixer

Narrowband Channel filter

2nd mixer

Complementary Filtering

Analogue Digital Converter

Baseband Signal Processing (Software)

Analogue Domain Digital Domain

Radio Domain Baseband Domain

Radio Domain <==> Analogue Domain

Baseband Domain <==> Digital Domain

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The Normative EnvironmentThe Normative Environment

• SDR Forum co-ordinates the activities world-wide– A generic approach mainly devoted to military

applications• Definition of software development approaches for simplifying

portability (SCA: Standard Communication Architecture)• Hardware implementation with FPGAs apart Baseband and

with general purpose processors for Baseband (for maximum flexibility and reconfigurability)

– Software development cost effectiveness is the target• Due to the huge amount of different systems and standards to

be implemented on the universal Hardware platform

– Equipment cost is not the major considered aspect

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General ContextGeneral Context

• Software Defined Radio is pushed strongly for military applications

– Due to the difficulties of interoperability with legacy equipment

• Need to communicate with a very large number of different

types of systems between the different armed forces,

different Countries, different components of the armed

forces (Air, Navy, Land forces, security forces)

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Software Radio for PMRSoftware Radio for PMR• Software Radio is also of primary interest for Private Mobile

Radio (PMR)– PMR is characterised by a large number of different systems

and standards in different frequency bands and with different bandwidths:

• Analogue systems • Narrowband (6.25 kHz)

• DMR (12.5 kHz)• TETRAPOL (12.5 kHz, 10 kHz)

• TETRA 1 (25 kHz)• APCO 25 Phase 1 (12.5 kHz)

• APCO 25 Phase 2 (12.5 kHz equivalent 6.25 kHz)• Wideband Data TETRA 2 TEDS (25, 50, 100, 150, 200 kHz)

• Wideband Data TIA SAM/IOTA (50, 100, 150 kHz)• And interest for PMR/PAMR/Public systems with GSM also

(or with other systems) on the same equipment

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Software radio for PMR: ObjectivesSoftware radio for PMR: Objectives

• Objectives– Reduce the development costs:

• A single Hardware Platform for several standards and systems

– Reduce the equipment costs• Use as much as possible ‘Off the Shelf’ Components

• Develop highly integrated components (ASICs) for specific functions (and applicable for the different systems and standards)

• Additional benefits– Reduction of size and weight of equipment

– Improved autonomy of equipment– Capability of evolution of systems and equipment

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Constraints for coexistence (Classical case)Constraints for coexistence (Classical case)

• Narrowband filtering early in the receiver chain means that:

– most of the interferers are rejected

– only closest ones are important (adjacent, alternate, …)

– blocking shall also be considered (Broadband noise of

the LO)

– useful signal is dominant in the signal that comes into

the Analogue/Digital Converter

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Constraints for coexistenceConstraints for coexistence(Software Radio case)(Software Radio case)

• Analogue/Digital Conversion is applied close to the antenna

– a whole band is then digitised:• not only the useful signal

• but also all the signals going through the wideband filter placed before the ADC

– Then contributors to interference are all the signals that are digitised

• not necessarily only adjacent and alternate• many interference signals can be present

• This means a need of large dynamic of the ADC because saturation of the wideband digital signal can damage dramatically the useful signal

– So the approach for measurement applied in PMR (LMR) standards is not totally well suited for Software Radio case

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Constraints for coexistenceConstraints for coexistence(Software Radio case)(Software Radio case)

• We need to avoid over-specification and over-testing– The constraints of the base co-existence standard EN 300 113 are in practise

relevant only when applied to an uncoordinated environment (Direct mode, or small systems with only few bands allocated for example)

– In a large system, a bloc of channels is allocated to the whole system• Interference (co-channel, adjacent channel, …) is limited thanks to adequate radio

planning and frequency reuse

• the protection limits (especially at receiver side) can be in practise relaxed in this case

• Then, for a software radio structure for example, the constraints in the whole digitised band are not necessarily the addition of the most stringent constraints of

EN 300 113

• The number of channels effectively contributing to interference needs also to be taken into account

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The Transmitter Chain caseThe Transmitter Chain case

• A similar problem can appear with the transmitter, for example, the following conditions:

– Combination at the Base station of several channels in digital before Digital/Analogue Conversion and Power

Amplifier– Multi-channel modulations (e.g. OFDM) where each sub-

channel is modulated and all sub-channels are combined in the same transmitted signal

– In these case problems of saturation in the DAC can also appear.

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ConclusionConclusion

• The Regulatory environment established in Europe under the

R&TTE Directive applies equally to Software Defined Radio

products

• Software Defined Radio products have the capability of

providing both flexibility in their application and early market

access for new products

• Software Defined Radio products have the potential to combined

radio systems to facilitate interoperability between potentially

incompatible systems