Overview Of SDR and Devices

Introduction to SDR

Software-Defined Radio (SDR): 소프트웨어로 정의된 라디오
Represents a significant shift in the way radio systems are conceptualized and implemented.
Traditionally, radio components and functionalities were primarily defined and managed through hardware.
This traditional approach posed limitations, especially regarding flexibility and the ability to adapt to new standards or frequencies
-SDR changes this paradigm by transitioning the definition and control of radio functions from hardware to software.
This shift began gaining prominence in the late 2000s, marking a new era in radio technology

Evolution of Radio Technologies

Hardware Radio Software-Defined Radio Software Radio
(1)Hardware Radio
:All componenets of the radio are made of hardware
-Traditional Approach: In the past, radio systems were predominantly hardware-based
This meant that the tuning and modulation of frequencies were physically managed by adjusting the hardware components
-Limitations: Such a system was inherently rigid
Adjusting to new frequencies or modulation techniques was challenging and often required substantial physical modifications to the radio system
(2)Software Radio
:All components of the radio are made of software
-Initial Concept: The idea of software radio emerged as a solution to the rigidity of hardware radio
It proposed the use of software for managing radio functions, such as tuning to different frequencies
-Challenges: However, early attempts at software radio faced difficulties, particularly in achieving the wide coverage and flexibility envisioned
Tuning across a broad range of frequencies efficiently and effectively through software alone proved challenging
(3)Software-Defined Radio (SDR)
-Balanced Approach: SDR represents a matured version of the software radio concept
It effectively bridges the gap between hardware and software in radio systems
-Advantages: SDR allows for much greater flexibility than traditional hardware radios
Adjustments to frequency, modulation, and even the radio’s fundamental behaviors can be made through software updates without the need for physical alterations
-Milestone Device:
The USRP1(Universal Software Radio Peripheral 1) is often cited as a pioneering device in the SDR domain, illustrating the practical realization of SDR concepts
Software-Defined Radio has revolutionized the radio technology landscape by providing unprecedented flexibility and adaptability
Through SDR, what was once a rigid and hardware-bound field has become dynamic and software-driven, opening up new possibilities for innovation and application in various domains, including telecommunications, military communications, and amateur radio

What is Software-Defined Vehicle?

-A vehicle that can control, operate, and update parts or the entirety through software
Vehicle can be controlled or updated partially or wholly through its software, highlighting the flexibility and adaptability of its functions. This is particularly relevant with the rise of electric and autonomous vehicles, where software plays a pivotal role in vehicle operation and updates can introduce new features or improvements without needing to change the vehicle’s hardware

-Cloud: The cloud symbol cloud computing services.
Vehicles can connect to the cloud to send and receive data. This data might include software updates, traffic information, maps for navigation, and user preferences
-Vehicle: Physical vehicle itself
Software-Defined Vehicle Platform: Central concept of the diagram.
Suggests that the vehicle’s platform is defined by software, meaning that much of the vehicle’s functionality can be controlled or modified through software. This makes the vehicle highly adaptable and upgradeable, similar to how one might update the operating system or apps on a smartphone
ECU/Network:
ECU stands for Electronic Control Unit, which is like the vehicle’s computer, controlling various functions
Network implies the vehicle’s internal communication network, which allows ECUs and other components to communicate with each other
Infotainment:
Vehicle’s entertainment and information system, which might include navigation, media playback, and connectivity to external devices
Sensor/Actuator:
Sensors gather data from the vehicle and its environment, such as speed, temperature, or proximity to other objects
Actuators are mechanisms that act upon this data, enabling physical actions like opening valves, moving parts, etc
Battery/Motor: The vehicle’s power source and propulsion system, which in electric vehicles are the battery and electric motor
-The concept of a Software-Defined Vehicle (SDV) emerges as part of a broader trend toward software-defined systems, including storage, cloud, and network solutions
-This trend signifies a shift from traditional, hardware-centric designs to more flexible, software-driven architectures
The foundation of this movement can be traced back to the development of Software-Defined Radio (SDR), which revolutionized radio technology by transitioning control and functionality from hardware to software

Software-Defined Series

Software-Defined Data Center
A data center that can control, operate, and update parts or the entirety through software

Software-Defined Data Center:
Data center where all infrastructure is virtualized and delivered “as-a-service”
This allows for the entire infrastructure to be controlled and operated through software, providing a more flexible, automated, and manageable environment
Automation:
Capability of the data center to manage and operate the systems automatically without human intervention, based on defined policies and rules
Orchestration:
Automated arrangement, coordination, and management of complex computer systems, middleware, and services
Management:
Overarching governance, administration, and control of the data center’s resources and services
Three pillars of the SDDC:
Compute Virtualization:
The virtualization of servers, where multiple virtual machines (VMs) run on a single physical server’s hardware, managed by a hypervisor
Storage Virtualization:
Pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console
Network Virtualization:
Process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network
Software-Defined Network
A network that can control, operate, and update parts or the entirety through software

SDN: An approach to networking that uses software-based controllers or application programming interfaces(APIs) to direct traffic on the network and communicate with the underlying hardware infrastructure
-It separates the network’s control(or management) plane from the data(or forwarding) plane
Applications: Software programs that use the network to communicate. They interact with the SDN controller to request network resources or services
Control Plane: Contains the SDN Controller, which is the central part of an SDN network. It maintains a comprehensive view of the network and makes decisions about where to send packets based on this view. The control plane is responsible for managing the network policies and traffic flow
SDN Controller: “Brain” of the SDN network. It provides the central point of control, using protocols like OpenFlow, to manage the flow control to the networking devices, like switches and routers
SDN Datapath: Flow tables that are installed on switches. These tables tell the switches how to handle different types of network packets
Data Plane: This layer is made up of the switches that perform the actual forwarding of packets based on the flow tables that have been set up by the control plane
Switches: In the context of SDN, these are the physical or virtual devices that forward packets across the network. In an SDN environment, these switches are programmable and can dynamically adjust and route traffic based on the SDN controller’s instructions
Pool of Application Servers: Servers that host applications and services. In an SDN architecture, the network can be programmed to optimize the delivery of data to and from these servers
Software-Defined Everything
-Software-defined Vehicle
-Software-defined Storage
-Software-defined Cloud
-Software-defined Network

Software-Defined Radio

-Radio that control and update via software
SDR is a type of radio communication system where components that have traditionally been implemented in hardware (e.g., mixers, filters, amplifiers, modulators/demodulators, detectors) are instead implemented by means of software on a personal computer or embedded system
-Necessary for conceptual learning and practical operation experience
To effectively utilize SDR, it’s important to understand the underlying concepts that enable software to define and control the radio’s functions. Additionally, hands-on experience with actual operation is essential. This experience helps in comprehending how software can manage various aspects of radio operation, such as signal processing, modulation, and frequency management

A schematic of the USRP (Universal Software Radio Peripheral)/SBX (SBX is a specific model of USRP that operates at a certain frequency range), which is a common piece of hardware used for SDR
-Signal processing path within an SDR system, specifically using a USRP(Universal Software Radio Peripheral) device
Starts with a Gain control, then passes through an Anti-aliasing filter with a 100 MHz cutoff frequency before reaching the Analog-to-Digital Converter (ADC), which converts the analog signal into a digital signal represented by x[n]
-The USRP2 N210 uses a port interface to initiate applications and has been expanded through such implementations
-The system has components that can be updated as needed
-The signal processing flow is: Gain → Anti-aliasing Filter → ADC (Analog to Digital Converter) → x[n] (digital signal representation)
-Plans to develop the framing, scheduling, and radiation components in software

Software-Defined Vehicle (SDV) and Related Technologies

Evolution from SDR to SDV
-Origin with Software-Defined Radio:
The journey began with SDR, which enabled radios to be dynamically programmed for different frequencies, protocols, and functions via software
This flexibility marked a significant departure from the static, hardware-defined radios of the past
-Expansion with USRP2 N210:
The USRP2 N210 device exemplifies the extension of software-defined principles beyond radio
It utilized ports and interfaces for applications, laying the groundwork for the software definition of various vehicle systems
The Software-Defined Vehicle Approach
Comprehensive Software Control:
In an SDV, critical components and functionalities, such as gain adjustments, anti-aliasing filters, and analog-to-digital converters (ADC), are managed through software
This approach allows for on-the-fly updates and adjustments, enhancing the vehicle’s adaptability and performance
Key Areas of Software Focus:
Framing and Scheduling: Software determines how data is organized and when tasks are executed, optimizing the vehicle’s operations and responses to real-time conditions. Radiation: The management of electromagnetic emissions, crucial for communications and sensor functions, is also software-controlled, allowing for greater precision and adaptability. Benefits of Software-Defined Vehicles The transition to SDVs brings several advantages, including: Enhanced Flexibility and Updateability: Vehicles can receive software updates to introduce new features or improve existing ones without the need for physical modifications. Customization and Scalability: Software allows for the customization of vehicle functionalities to meet diverse user needs and preferences, as well as the easy scaling of solutions across different models and platforms. Improved Performance and Efficiency: By optimizing software algorithms and processes, SDVs can achieve better fuel efficiency, lower emissions, and improved overall performance.

발표자의 Credential

Spectrum challenge 참여
Research aims at efficient spectrum use

Basic Concept of Radio

Point-to-Point Communication
A direct communication link where information travels from one point (the transmitter) to another point (the receiver)

-Direct communication link from one point (the transmitter) to another (the receiver)
-Information travels through a channel which can be air, space, or cable
Transmittor

(1)Symbol Mapping
Converts binary data stream (b[n]) into symbols
In BPSK, binary ‘0’ is mapped to -1 and ‘1’ to +1
Example: Raw digital signal [0, 1, 0, 0, 1] becomes [-1, +1, -1, -1, +1]
(2)Upsampling
Increases the symbol rate by inserting zeros
Upsampled example: [-1, 0, 0, 0, +1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, +1, 0, 0, 0]
(3)Pulse Shaping
Applies a raised cosine filter to the upsampled signal
Minimizes intersymbol interference (ISI) and prepares the signal for transmission
(4)Modulation
The shaped signal is modulated with a cosine carrier wave $( \cos(2\pi f_c t) )$
Transfers the data to a suitable frequency band for transmission
Receiver

(1)Matched Filter:
Uses a filter similar to the transmitter’s raised cosine to optimize signal-to-noise ratio
Helps distinguish the symbols clearly amidst noise
(2)Frequency & Time Synchronization:
Corrects frequency and timing misalignments due to Doppler shifts and propagation delays.
Aligns the received signal with the receiver’s reference for demodulation.
(3)Downsampling:
Reduces the sample rate to match the original symbol rate
In our example, the sequence returns to one sample per symbol
(4)Symbol De-Mapping:
Converts the filtered symbols back into the bit stream.
The symbol de-mapping process then reverses the modulation from the transmitter, restoring the modulated symbols to the original bit stream
Example: Received symbols close to -1 or +1 are mapped back to ‘0’ or ‘1’
Recovered bit stream [0, 1, 0, 0, 1] matches the original signal
Transmitted data takes the form of an analog signal shaped for transmission
Radio communications include filtering to manage noise and recover sample data
All modules are hard-coded or statically set; in hardware, adjustments are limited
Frequency adjustment is symbolized by the cosine function $(cos(2π))$
The entire process depicts how data in its raw digital form is transformed, transmitted, and then received as an analog radio signal
The recovered data at the receiver end should match the original digital signal if all steps are properly implemented

Hardware Radio에서부터

라디오 돌리는 거를 통한 tuning
예전에는 analog 자체를 조절
SDR는 안테난나 tuner AL, FL, 와이파이 수신기가 됐다가 변환 가능 (다른 거랑 비교)
군 쪽 수신자만 아는 형태로 송수신 다변환하려고 함

SDR 개념

Application -> TCP/IP -> MAC (Framing, Link MGmt, SCheduling) -> Physical(FEC< Multiplexer < Modem -> Digital Tuner -> ADC -> Tuner/Filter/AMP
-RTL SDR 대표적
Software tuning 가능하다고 알려짐
$25
AM, FM만 가능
Hackrf1 $150, $160
-Software Defined Radio Platform
다양한 거 존재 Software 최대화, HW 최소화
-기존 하드웨어 라디오 경우 시스템 구조내부 수정이 난해함
통신 시스템 관련된 다양한 실험을 하기 어려움

-안테나
AM용도
다이어그램 형태로 띄워서 운용
주파수 뭐로 틀까요? 107.7
신호를 볼 수 있음
Graph = GNU python 사용시 line by line
Companion, block 단위 구현
=> 간단히 GNU Companion, 파이썬 code level
Python module들은 만드는 블록은 대체로 C++, 파이썬

SDR Open source Ubuntu 돌릴 수 있음

중간 Summary

-Wifi, LTE, …HW로 핵심엔진, 위에 Processor, 위에 OS, 하나의 통신 장치 Wfif는 wifi만, Bluetooth만 되거
Software defined radio 어떨 때는 WIfi, LTE, 트랜스포머가 되는 장치로 구현 가능, 이유는 H/W가 최소하됨
Analog -> DIgital , Digital -> Analog 왔다가는 필수 HW로 최소 나머지 신호 처리 , Software로 지웠다가 썼다가 통신 장치가 변할 수 있게 해줌 하나의 장치로 원하는 대로 필요할 때마다 사용 가능, 작게, 원할 때마다 바꿈. Smartphone에 LTE, 5G, 너무 비쌈
그런데 하나인데 원하는대로 바꾸는 거 가능. 그러면서 가격이 1/10, 1/20

실습

짙은 부분이 signal 있는 것 Fequency Display, Waterfall display, time domian display, constellation display 가능
FM, AM 가능
안테나따라 신호 크기 달라짐
End
Audio Sink
Replay file source 등 다양한 블록 존재
Example:
fft찾겠다 -> find block -> block appears -> Connnect it

보안 학생들 물리계층 보안 RF ADC FFD 정보 이용해 보안 목적 실험 가능
공격자 RF

SDR 개념

-이상적인 SDR 경우 (Ideal SDR)
Connect Antenna to an ADC/DAC
Sampling frequency limitation in RF Dynamic range limitation
Hardware filter low signal, there is -실질적인 SDR의 경우 (Practical SDR)
0TUnable RD front end implemented in software
All digital signal processing in software
5G, mm wave 28G Hz 실험… Giga pont 어마어마하게 늘림
10Gbps 만 가능? 다양한 거 cover 위해 SDR
4G 5G SRS software 전용 platform 존재
변조 다양하게 할 수 있는 ursp 위주로 실습

SDR 구조 및 기본 구동

Digital 신호 처리를 SDR platrform 진행 Pulse shaping/ PC -> HW(Pulse Shaping Up/Down Conversion) ->HW (DAC/ADC RF Front-End (HW))
PC 대신 다른 거 가능.

Tips

AI 기반 통신 가능 USRP radio 바꿔보면서 채널 상태 정보 수정 가능 wifi가지고 sensing, 환경을 인지… 채널 상태 수집, 사람 서있고, 수신 가능

USRP

Universal Software Radio Peripheral
Ettus Re

Silver box:FM 전용
URSP1 -> USRP2/ USRP N210 -> USRP X Series

SDR 디바이스

-디바이스 종류
wikipedia
list of software-defined radios
LimeSDR 잘 팔림

RTL-SDR

RTL2832U 칩 기반의 초저가 전용 SDR
저가용 SDR하드웨어
HackRFOne 알리 express

SDR 사용 방법

-Hardware Driver Installation
-USRP?RTL-SDR/HackRF have their own version of driver
Example: UHD(https://github.com

Driver 파라미터 가지고 조정
GNUradio
-Two methods for the operation
Method1: gnuradio-companion (GRC)
Similar to Simulink or Labview
왠만하면 module만들어서 Python 연결하는게 젤 best
-귀찮을 때 송신만 해서 보고 싶음
Block 단위로 만들어서 transmitter 끌어다와서 함
Module1 -> Module2(C++) -> Open source software for SDR

SDR별 사양

-USRP
ADC Rate 단독으로 써러 wifi 힘듬
대체로 25MHZ 씀 -RTL-SDR
ADC rate, Max Bnadwidth는 알고 쓰자 ex. HackRF one 가지고 40MHZ 가지고 쓰기 힘듦
-HackRF One(2020년 이전 버전 기준)

USRP190 동일 제품에서도 어떤 interface 쓰느냐, 등등의 interface 차원의 고려 필요

실습

OFDM Transmitter 블락 형태
estimation, modulation, 어떤 방식으로 쓰이고,
GRC에서 돌리면 fm_reciever_test.grc 돌리면 python code가 나옴

Ubuntu20.04 LTS GNU vesrion

마무리

이일구 교수님
-Hardware, 고성능, 빠른 처리 가능
-Software로 만들면 실제로 성능이 안 좋아짐
높은 주파수, bit 수가 늘어나도 느려짐
Parallel하게 처리
Software, 성능 열하
ADC 중요 component 16bit, 8bit
Software 시도시 bit 수 늘리기 어려워서 해상도 낮추고, software 안정성, 품질 보장하기 힘듦
미래에는 chip하나로 Software 가능
IOT:저가의 저전력의, 장치 만들기 가능? 안 됨
SOfware firmware 업데이트하도록하는게 미래의 SDR
FOTA: Connected car 주차시 LTE로 firmware 업데이트
SDR 동작 가능 특징 업데이트 가능한 세상이 찾아올 예정
SDR

Extra Study:
httpsL//engineering.purdue.edu/discovery/2014_1.research-aims