range calculation

Software Defined Radio (SDR) : 

Software Defined Radio (SDR) David Sittner November 19, 2008 EGGN 516

How does it work? : 

How does it work? Ideal Software Radio

How does it work? : 

How does it work? SDR with the USRP and GNUradio

Conclusions : 

Conclusions SDR provides flexibility; one device can perform many functions SDR provides versatility; many different functions can be performed as needed while running without need for human interaction Ideal SDR is limited by the speed and resolution of analog-to-digital converters Signal and data processing is limited by the speed of the computer

Transmitter : 

Transmitter

Transmitter : 

Transmitter Amplifier: ZHL-30W-252+ Limiting Factors: 1dB compression point: 44dBm @ output IP3 point: 52dBm @ output 1dB compression point affects maximum output power IP3 point affects maximum linear output No = -45.14 dBm DRf (dB)= (2/3)*(P3 (dBm) – No (dBm)) = 64.76 dBm Maximum spurious-free output = 19.62 dBm Maximum output = 44 dBm

Receiver : 

Receiver

Receiver : 

Receiver Analog to Digital Converter Limiting Factors: -1 V to +1 V range with 200 ohm input 12 bit sample resolution 20dB variable gain amplifier to maximize resolution 64 MHz sampling frequency limits bandwidth to 32 MHz Minimum received power at input for full 12 bit resolution: -16 dBm

Transmission : 

Transmission Pt = 44 dBm for maximum output = 19.62 dBm for spurious-free output Nt = -45.14dBm Pr = (Gant λ/4πR)2 * Pt Nr = (Gant λ/4πR)2 * Nt The Friis Formula:

Conclusion : 

Conclusion For spurious-free transmission, the received signal reaches the minimum allowed for full 12 bit resolution at a range of 37 meters. The SNR at this range is 52.5 dB

Conclusion : 

Conclusion For maximum allowed transmission, the received signal reaches the minimum allowed for full 12 bit resolution at a range of 612 meters. The SNR at this range is 52.76 dB