SDR EXPLORER KIT

A PC BASED SOFTWARE DEFINED RADIO LAB KIT

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SDR LAB KIT is a PC based software defined radio (SDR) platform for designed for B-Tech / M-Tech & Phd students to conduct Lab experiments. Students can conduct different communication laboratory experiments and can feel the real time communication using SDR LAB KIT. It is a 2X2 MIMO or 1X1 SDR Platform with USB 3.0 based Host(PC) interface. The hardware architecture covers 50 MHz to 6 GHz with a channel bandwidth of 200KHz to 56MHz. SDR LAB KIT board comes with driver support for Windows and Linux operating systems. SDR LAB KIT boards are integrated directly with MATLAB, SIMULINK, LABVIEW, MS VC++, MS VC# and soon with GNURadio. LABVIEW Executables will be provided to conduct different experiments in the field of communication. SDR LAb kit is USB bus powered and plug and play.

With a PC Based SDR LAB Kit, Stundents, reserchers and R&D houses are greatly benefitted since SDR LAB Kit is capable of generating and receiving such a wide variety of waveforms in no time and can be visualised at varius stages of signal transmission and reception. This helps in getting key insights of a realtime communication system and its parameters. Apart from conducting various experiments with different modulation shcemes, it provides greater understanding of performance related issues regarding link budget of a wireless link for example fade margin, minimum SNR and path loss calculations. Wireless channel impairements like AWGN noise, Multipath which leads to ISI issues can be readily visualised while transmitting and receiving signal in the RF. Due to ultrawide tuning capability of this SDR LAB Kit, the behaviour of a wireless channel at frequencies down from 50MHz to 6GHz can be studied.

Spectrum of Applications supported with SDR Starter Kit

Type: Single Carrier : Support: AM, PM, FM, BPSK, QPSK, QAM, MSK, other variants

Type: Multi Carrier : Support: OFDM, OFDMA, SC-FDMA, MC-CDMA

Type: Multi Antenna : Support : MIMO, Beam forming, SDMA, Spatial Diversity and Multiplexing

Type : Communication standards : Support: 3GPP: CDMA2000, TD SCDMA, 1xEVDO, WCDMA, GSM, LTE

Type : Communication standards : Support : IEEE : WIMAX 16a,16d,16e, 802.11a/b/g/n, ZigBee, Bluetooth, RFID

Type : Broadcast Technology : Support : DVB(set top box), DAB (world space)

Type : Others ; Support : Radar, SIGINT, COMINT, MILCOM

A CASE STUDY ON DESIGNING OF OFDMA BASED COMMUNICATION SYSTEM WITH IMPROVED PAPR

An OFDMA Based communication system is aimed to be desined with improved PAPR. OFDMA modulation scheme is being adopted in all the modern communication systems for its robust performance in highly fading channels and for high bandwidth applications where the high symbol rates are directly prone to Inter-Symbol-Interference at the receiver. However, OFDMA scheme being the best choice it has its own inherent problems with Inter-Carrier-Interference and Peak-To-Average Power Ratio, leading to severly affecting the Power Amplifier efficiency. There have been many approaches proposed to reduce PAPR. Here we aim to explore all the possibilities and provide a much better solution. The approch to design will be

1. Understanding of a Modern Communication System and its parameters

2. Understanding of OFDMA Based system

3. Understanding of Communication Channels (Noise-AWGN), Multipath(Rayleigh/Rician) and their impact on wireless signals

4. Understanding of Synchronisation in comunication Receivers

Following a thorough study, a Simulation model is aimed to be developed in MATLAB for the OFDMA system. This will include

1. A random source of data generator

2. Scrambler for data whitening

3. Encoder for bit error correction

4. Interleaver for burst error correction

5. BPSK/QPSK/16QAM symbol mapping for first level modulation for data carriers

6. BPSK pilot symbol mapping for pilot carrier

7. IFFT for the mapped sub-carriers for second level of modulation and forming OFDMA symbols

8. Addicing Cyclic Prefix for countering ISI at the receiver

9. Adding Preamble for synchronization at the receiver

10. Synchronizer at the receiver for time/frequency offsets

11. OFDMA Demodulation and decoding along with Zero forcing Equalizer for removing channel impairements

12. BER measurement

Below is the block diagram of the proposed simulation

FIGURE1: OFDMA BASED COMMUNICATION SYSTEM

FIGURE2: OFDMA BASED COMMUNICATION SYSTEM SIMULATION VISUALIZATION

After the simulation, a method to improve PAPR is aimed to be simulated to show the performance improvements. Following the successfull simulation, the work is further aimed to demonstrate on a Hardware Platform(SDR LAB kit) which will directly connect with MATLAB for producing realtime transmission and reception of signals over the desired RF range and thus providing RF in the loop. This is essentially to proove the practical adoption of the proposed approach in the true wireless systems. This demonstration will conclude the aim and objective as desired.