1 Summary of SDR Analog radio systems are being replaced by digital radio systems for various radio applications. SDR technology aims to take advantage of these programmable hardware modules to build an open-architecture based radio system software. SDR technology facilitates implementation of some of the functional modules in a radio system such as modulation/demodulation, signal generation, coding and link- layer protocols in software. “…radios that provide software control of a variety of modulation techniques, wide- band or narrow-band operation, communications security functions (such as hopping), and waveform requirements of current & evolving standards over a broad frequency range…”

2 Problems in Communication Industry Commercial wireless communication industry is currently facing problems due to constant evolution of link-layer protocol standards (2.5G, 3G, and 4G), Existence of incompatible wireless network technologies in different countries inhibiting deployment of global roaming facilities Problems in rolling-out new services/features due to wide-spread presence of legacy subscriber handsets.

3 Solutions using SDR SDR technology enables implementation of radio functions in networking infrastructure equipment and subscriber terminals as software modules running on a generic hardware platform. SDR technology supports over-the-air upload of software modules to subscriber handsets SDR technology has some drawbacks like higher power consumption, higher processing power (MIPS) requirement and higher initial costs e.g., SDR may not be appropriate for pagers.

4 Features of SDR Reconfigurability: SDR allows co-existence of multiple software modules implementing different standards on the same system allowing dynamic configuration of the system by just selecting the appropriate software module to run Ubiquitous Connectivity: SDR enables implementation of air interface standards as software modules and multiple instances of such modules that implement different standards can co-exist in infrastructure equipment and handsets. Interoperability: SDR facilitates implementation of open architecture radio systems. End-users can seamlessly use innovative third-party applications on their handsets as in a PC system.

5 Goal: To convert RF signal to audio frequency, thus maximizing flexibility and minimizing hardware. Goal: To convert RF signal to audio frequency, thus maximizing flexibility and minimizing hardware. 16 Bit Sound cards have a sampling rate up-to 44KHz. 16 Bit Sound cards have a sampling rate up-to 44KHz. Sound cards have built in antialiasing filters. Sound cards have built in antialiasing filters. Mixing of frequencies gives rise to “image frequencies”, which cannot be avoided using the filters. Mixing of frequencies gives rise to “image frequencies”, which cannot be avoided using the filters. RF to Sound Card

6 Image Frequencies. Results of mixing frequencies: Primary Output Signals F©+F(lo)= MHz MHz= MHz F©-F(lo)= MHz MHz= MHz Imaging frequencies – Not Desired -F©+F(lo)= MHz MHz= MHz -F©-F(lo)= MHz MHz= MHz

7 The principle is that by delaying the RF carrier frequency by 90 deg and forming a quadrature Q signal and then using it in conjunction with the in phase “I”, we can compute the amplitude and phase of the signal. The principle is that by delaying the RF carrier frequency by 90 deg and forming a quadrature Q signal and then using it in conjunction with the in phase “I”, we can compute the amplitude and phase of the signal. Eliminating Image frequencies- Quadrature Mixing

8 DSP in the Frequency Domain SDR-1000 Uses fast Fourier transform (FFT)  Converts the complex I and Q discrete-time signals into the frequency domain  The output can be thought of as a large bank of very narrow band-pass filters, called bins  Each bin measures the spectral energy within its respective bandwidth Frequency m t =( I t + Q t ) 22 1/2 t =tan (Q t /I t ) With I and Q we can demodulate AM signals directly using these equations  The 3-db points overlap to provide linear output

9 The SDR 1000 covers frequencies from 16 KHz-65 MHz The SDR 1000 covers frequencies from 16 KHz-65 MHz The frequencies at which the testbed operates is 915MHz, 2.4 GHz and 5.7 GHz. The frequencies at which the testbed operates is 915MHz, 2.4 GHz and 5.7 GHz. How can we integrate the two applications ? How can we integrate the two applications ? Applying SDR with current Testbed

10 Bibliography

11 Visual Basic Algorithms for SDR  Visual Basic can be used to create software based algorithms that allow different frequency band transmissions without any additional hardware  Past: Radios have integrated FM/AM receivers  Future: SDR will eliminate any additional hardware while modulating/demodulating any given frequency signal

12 Visual Basic Algorithms for SDR The use of SDR will allow any given frequency to be transmitted into any given band such as FM, AM, QSPK, BPSK, etc. The use of SDR will allow any given frequency to be transmitted into any given band such as FM, AM, QSPK, BPSK, etc. All frequency band algorithms will be integrated in the software as well as the signal processing convergence of analog to digital and vice-versa (DSP) All frequency band algorithms will be integrated in the software as well as the signal processing convergence of analog to digital and vice-versa (DSP) The software development of this project will demonstrate data transmission via multiple frequency bands and provide a GUI for output generation and verification The software development of this project will demonstrate data transmission via multiple frequency bands and provide a GUI for output generation and verification

13 Tasks Achieved this week Each member familiarized themselves with the concept of Software defined radio by reading material posted on websites like for example, Nishant gave the group a demo of how SDR was actually working. Group was divided so as to work on the “software” and “hardware” aspect of SDR. Audrey and Oscar shall work with Nishant to understand the source code. Angelo, Amitoj and Kwesi would work on the hardware part of SDR and the testbed.