# Presentation: 483006

## SDR Technology Implementation forthe Cognitive Radio

**SDR Technology ****Implementation for****the Cognitive Radio**

**Bruce Fette PhD**

**bruce.fette@gdds.com**

***Chief Scientist***
***General Dynamics Decision Systems***

**Notes:**

It is important to note that SDR is not really a new technology or term.  Software defined radio or SDR was originally coined by Dr. Joe Mitola in 1991to signal the shift from dedicated single-purpose, hardware intensive radios of the 1980’s to the multi-band, multi-mode software defined radios that began to appear in the military in the 1990s.  In fact, IEEE first published SDR technology in its IEEE Transactions on Communications in 1992.

In 1995, the SDR Forum was organized to begin to develop standards for SDR.  The SDR Forum is a completely voluntary, interdisciplinary consortium that includes corporations and technologists from around the world.  

## Cognitive Radio* is Built on SDR*

**We must start with a Software Defined Radio as a basic platform on which to build a Cognitive Radio**
**Cognitive Radio can provide the spectral awareness technology to support FCC initiatives in Spectral Use**

- *SDR and Cognitive Radio are terms coined by Dr. Joe Mitola - see appendices for references

**Notes:**
Before Explaining Cognitive Radio and its capabilities, we need to provide background about what an SDR is, because an SDR platform serves as the basis upon which a Cognitive Radio is built.

## Definition of SDR

**From FCC NPRM*: “We view software defined radios as the result of an evolutionary process from purely hardware-based equipment to fully software-based equipment. In this regard, the process can be roughly described in three stages**

**1. Hardware driven radios:** Transmit frequencies, modulation type and other radio frequency (RF) parameters are determined by hardware and cannot be changed without hardware changes.
**2. Digital radios:** A digital radio performs part of the signal processing or transmission digitally, but is not programmable in the field
**3. Software Defined Radios:**. All functions, modes and applications can be configured and reconfigured by software.

- *Notice of Proposed Rule Making (NPRM) 8/12/00

**Notes:**
As you may already know, in August of 2000 a Notice of Proposed Rule Making or NPRM was issued.   In this notice, the FCC created the case for SDR as the next operating standard for radio and related RF communications.

Under point 1: the transmit frequencies, modulation type and other radio frequency (RF) parameters are determined by hardware and cannot be changed.

Under point 2: Processing may be done by digital signal processors, by fixed programs stored as firmware, or by dedicated hardware such as application-specific integrated circuits or ASICs. These systems do not have forward flexibility to implement future protocols.

Under Point 3: A software radio can do something new after it is shipped, that was not specifically designed by the factory at time of manufacture.

Under Point 5
	-Standardized hardware interface 
	-Standardize operating Environment  (OS equivalent)
	-Standardized Interface from Waveform applications to Operating Environment
	-Standardized hardware/RF services
	-Multiple capabilities in a single platform
I can’t go into the full details of the standardized hardware and software architectures, however, in the appendices, there is a detailed diagram of just what  SDR means in real world applications.

## Definition of SDR - Continued

**SDR Forum:**
**4. **SW defines all waveform properties, cryptography and applications,  is re-programmable, and may be upgraded in the field with new capabilities
**Importance of Standards (APIs)**
**5. **HW Interfaces, RF services, Operating Environment, Application to Radio Interfaces

**Notes:**
As you may already know, in August of 2000 a Notice of Proposed Rule Making or NPRM was issued.   In this notice, the FCC created the case for SDR as the next operating standard for radio and related RF communications.

Under point 1: the transmit frequencies, modulation type and other radio frequency (RF) parameters are determined by hardware and cannot be changed.

Under point 2: Processing may be done by digital signal processors, by fixed programs stored as firmware, or by dedicated hardware such as application-specific integrated circuits or ASICs. These systems do not have forward flexibility to implement future protocols.

Under Point 3: A software radio can do something new after it is shipped, that was not specifically designed by the factory at time of manufacture.

Under Point 5
	-Standardized hardware interface 
	-Standardize operating Environment  (OS equivalent)
	-Standardized Interface from Waveform applications to Operating Environment
	-Standardized hardware/RF services
	-Multiple capabilities in a single platform
I can’t go into the full details of the standardized hardware and software architectures, however, in the appendices, there is a detailed diagram of just what  SDR means in real world applications.

## SDR Technology

**  ****Technology fundamentals:**
- Digital Signal Processors (DSPs) provide virtually infinite programmability
- All modulation, cryptography, protocols, and source coding (voice, data, imagery) are established using software
- Many types of modulation can be accomplished over a broad range of frequencies, thereby an SDR is capable of servicing more than one class of service
- Field serviceable, when requirements change, upgrades and modifications are relatively easy to execute

**Notes:**
Standardized software interfaces enable software portability to multiple hardware architectures.
SDR Forum software standards/processes define operating environment and resource management in a way that is similar in concept to an OS.
Then, the hardware abstraction Layer (HALWG) defines API interfaces for external equipment interfaced to SDR software drivers as well as API interfaces for standard internal hardware interfaces.

SDR isn’t ‘smoke and mirrors’ either, software defined radios are operational and available today
GD-DS has deployed software defined radios such as the DMR and PRC112G to US DoD, UK MOD
Harris currently ships the PRC117F to DoD
Airnet uses SDR technology for its GSM basestation
And many more announced SDR products are in development:
Vanu, JTRS Cluster 1, etc 
with many new commercial products scheduled for release in the next 3 years

## SDR Standardized Architecture Supports Both Current and Future Applications

**SDR Standardized Architecture Supports Both Current and Future Applications**

**FDMA, TDMA, CDMA, TDD**
**AM, FM, MFSK, MPSK, MQAM, CPM, SSB, DSSS ... **
**DES, 3DES, AES, MeXe**
**Trunked Radio, APCO-25, GSM, Iridium, 802.11..**
**Tone Coded Squelch, CVSD, LPC, VSELP, AMBE, ....**

***It’s just a matter of software!***

**Notes:**
It is the equivalent to the  PC that replaced the typewriter and the internet that replaced the teletype, the capability to mold your available resources to meet your needs.

## Building the Cognitive Radio using SDR Technology - The SDR Radio is Available Now!

**SDR drives the Cognitive Radio concept that will provide the spectral awareness technology supporting the FCC’s Spectral Use initiatives**
**SDR is a proven, flexible,  COTS technology platform **
**SDR Technology is in Production and Available Now**

**New **
**Announcements**
**Coming **
**Soon**

**Notes:**
At this point it is important to see that SDR is a product of Technological “Natural Selection”. It is an obvious and AVAILABLE, technological “next step”. 

## Cognitive Radio Means “Smart” and “Alert” 

**It knows where it is**
**It knows what services are available, for example, it can identify then  use empty spectrum to communicate more efficiently**
**It knows what services interest the user, and knows how to find them**
**It knows the current degree of needs and future likelihood of needs of its user**
**Learns and recognizes usage patterns from the user**
**Applies “Model Based Reasoning” about user needs, local content, environmental context**

**Notes:**
An extension of SDR employs “model based reasoning about user needs, local content and environmental context...
Think of it as a PDA with a radio that is so smart that it solves simple stuff on its own 
round peg - round hole; 

## How Does a Cognitive Radio Get So Smart?

- Mitola, “Cognitive Radio for Flexible Mobile Multimedia Communications”, IEEE Mobile Multimedia Conference, 1999, pp3-10

**Notes:**
Mechanisms for flexible pooling of radio spectrum using a new class of protocols “formal radio etiquette”

The radio learns.

As we learn important etiquettes and plug them into an SDR, along with enough smarts to choose the proper etiquette for the proper circumstances.

The degree of sophistication is practical where the radio architecture provides sufficient resources to support the protocols.

## Example Spectral Awareness Etiquette That Can Be Implemented on Existing SDR / Cognitive Radio

**Infrastructure Based Approaches**
- Possible Infrastructure Reuse - spread economic support base
- Existing examples of Spectrum sharing Protocols
- A) Trunked radio
- B) Cellular spectrum borrowing
- C) Demand Assigned Multiple Access (DAMA)(demand assigned time sharing)
- Infrastructure Supports wide Range of Spectrum Management Policies
- Match Requirements, Priorities, Spectral Mask of Owners

**Notes:**
Many Commercial applications already have support infrastructure, and the support infrastructure allows a high degree of sophistication in spectral awareness, protocol - etiquette, and responsiveness to policies of the spectral owner.

Within this context, spectrum sharing domains include:
Trunked Radio is a valuable example of the success of TASI sharing - 20X demonstrated or more where user community is aggregated to the 50 Erlang level or more
Public Safety - Be sure that priority and preemption provide high QoS to public safety
Cellular - service sharing can provide expanded coverage for both cellular, public safety, and federal services in regions where neither is economical on a stand alone basis
TV - great opportunities in T-F-C-S sharing

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Cognitive Radios can adopt new etiquettes for new standards
- Possible Demonstrations using existing SDRs
- Spectrum rental transactions
- Spectral Availability (Borrow) Beacon
- Local Spectrum Utilization Database Server (time, freq, code, space, power, modulation)

-     Spectral Noise temperature (Kolodzy, 2002)
-     RTS - CTS handshake (handshake includes local spectral activity   	model at each end of link, as well as BW, packet size, TX PWR 	for APC). Minimizes hidden node problem
-     Underlay, Overlay, Interweave

**•  ****Distributed techniques - Possible Demonstrations**

**Notes:**

Infrastructure Based Approaches:
Existing examples of Spectrum sharing Protocols
A) trunked radio
B) Cellular spectrum borrowing
C) DAMA demand assigned multiple access (demand assigned Time sharing)
Cognitive Radios can adopt new etiquettes for new standards
Possible Demonstrations using existing SDRs
A) Spectrum rental transactions
B) Spectral Availability (Borrow) Beacon
C) Local Spectrum Utilization Database Server (time, freq, code, space, power, modulation)

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

## SDR Finds Frequency - Time Opportunities 

- Spectral Awareness Etiquette

**Existing Signals**

**Detailed Signal Parameters**

**Deployed waveforms**

**Notes:**
Our SDR can search the spectrum, gather activity statistics, modulation properties, and choose frequencies that can be used for additional spectral use.

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

## Opportunities for Spectral Reuse Amongst Periodic Signals

**Notes:**
Even in active Spectrum there is great opportunity to use the spectrum, providing that waveforms are selected for orthogonal properties and that cross purpose interference is managed through antenna beam forming.

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

## Time - Frequency - Space 

**Each Domain has Opportunities for Spectral Reuse**

**T1**

**R1,R4**

**T2**

**T3**

**R3**

**R3,T4**

**Interfering**
**Signal Placed**
**In Null**

- Transmitter forms Beam Toward Intended Recipient
- Receiver forms Null Toward Interference Sources

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

- Adaptive Bit Loading onto OFDM carriers based on SNR

## OFDM Interference Avoidance

***OFDM Interference Avoidance***

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

- Adaptive Bit Loading onto OFDM carriers based on SNR

- OFDM techniques where small spectral holes can be filled by one or
- a few carriers that fit the time - frequency hole

## OFDM Carriers Selected for Use That Fall into Available Spectrum

- Frequency

- T

- I

- M

- E

**     ****Spectral  Adaptation Waveforms**

**OFDM Carriers Selected for Use That Fall into Available Spectrum**

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

- Adaptive Bit Loading onto OFDM carriers based on SNR

- OFDM techniques where small spectral holes can be filled by one or
- a few carriers that fit the time - frequency hole

- Interference Suppression & MultiUser Decomposition

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

- Adaptive Bit Loading onto OFDM carriers based on SNR

- OFDM techniques where small spectral holes can be filled by one or
- a few carriers that fit the time - frequency hole

- Interference Suppression & MultiUser Decomposition

- Importance of Adaptive Power Control
- AD Hoc Networking (shortest hop routing w APC)

## Transmitting from A -> Z : AdHoc Networking

- Node A

## Example Spectral Awareness Etiquette Can Be Implemented on Existing SDR/Cognitive Radio (continued)

- Waveform Orthogonality: Time - Freq - Code - Hop/Chirp - Spatial      - Usually Involves some form of CSMA sensing for high priority user

- Adaptive Frequency  - find a frequency

- Adaptive TDMA - find an unused time slot in between a periodic user

- Spatial - Beam steering and Null Steering

- Adaptive Bit Loading onto OFDM carriers based on SNR

- OFDM techniques where small spectral holes can be filled by one or
- a few carriers that fit the time - frequency hole

- Interference Suppression & MultiUser Decomposition

- Importance of Adaptive Power Control
- AD Hoc Networking (shortest hop routing w APC)

## Timeline: SDR’s  to have Cognitive Capabilities

- 2003

- 2004

- 2005

- 2006

- 2007

- 2008

**DARPA’s**
**Demonstrations**
**within 1 year**

**Commercial**
**viability**
**exploration &**
**commercial**
**analysis under**
**existing**
**agreements**

**Viability**
**demonstrated**
**for commercial**
**purposes**
**within 2 year**

**SDR Forum can**
**initiate early work**
**and insert into **
**standards bodies as**
**work matures**

**5 years for**
**etiquettes**
**to be formally**
**standardized**

- 2003

- 2004

- 2005

- 2006

- 2007

- 2008

**Notes:**
The FCC’s cognitive radio is fully realizable using today’s SDR technology.

## In Conclusion

**SDR Products and Technology are a Reality Today**
**SDR Standards are Actively Being Worked today by Standards Bodies and Organizations**
**Cognitive Radios have the Ability to Implement Protocols and Policies Beyond Traditional Communications. **
**New Realms of Knowledge and Information Transfer are Achievable with Cognitive/SDR Radio as the Underlying Technology Enabler**

## Appendix

**SCA Reference Architecture**
**Radio Services for Application Portability**
**SDR Forum Standardized Hardware Architecture**
**Reference Publications**

## SCA Reference Architecture

## Radio Services For Application Portability

**Radio Services For Application Portability**

**Operating**
**Environment**

**Devices**

**Radio Systems**
**Applications**

**Middleware**
**Services**

**(Ext)**

**(Ext)**

**(Ext)**

**(Int)**

**(Int)**

**(Int)**

**JTR Set**

**Radio**
**Services**

**(Ext)**

**(Int)**

**(Int)**

**WF**
**Apps**

## SDR Forum* Standardized Hardware Architecture

**SDR Forum* Standardized Hardware Architecture**

**From Programmable Modular Communications System (PMCS) Guidance Document, 1997**

## Reference Publications

- Mitola, “Cognitive Radio for Flexible Mobile Multimedia Communications”, IEEE Mobile Multimedia Conference, 1999, pp3-10
- Mitola, “Future of Signal Processing - Cognitive Radio”, Keynote, IEEE ICASSP, May 1999
- Mitola, Maguire, “Cognitive Radio: Making SW Radios More Personal”, IEEE Personal Communications, August 1999, pp13-18
- Mitola, “SDR Architecture Refinement for JTRS”, Milcom 2000, pp 214-218
- Mitola, “Software Radio Architecture: A Mathematical Perspective”, IEEE J on Selected Areas in Comms, April 1999, pp 514-538
- Margulies, Mitola, “Software Defined Radio: A Technical Challenge and a Migration Strategy”, 1998, pp551-556