GUIDED BY: Prof. DEBASIS BEHERA Phase Locked Loop Design for Transmitting and Receiving Sections in Optical Wireless Access PRESENTED BY : SITANSHU PATI SUBHRANSU SEKHAR NAYAK RAJESH KUMAR MUDULI SUMAN PANI GUIDED BY: Prof. DEBASIS BEHERA
CONTENTS : Project Framework Introduction Fundamentals of PHASE LOCKED LOOP Basic components of PHASE LOCKED LOOP Response of PLL Implementation in optical access Future work References
WHY THIS PROJECT 3
Project Framework System Level Design Process (Mathematical Model Simulation) Digital Parts - Frequency Divider - Phase Detector Analog Parts - Low pass filter(LPF) - Voltage Controlled oscillator - Crystal Oscillator - Frequency Synthesizer Design Synthesis and design layout Design Implementation to FPGA Digital parts and analog parts are implemented in circuit board to operate all system
FUNDAMENTALS OF PHASE LOCKED LOOP (PLL) Phase locked loop is a circuit which synchronizes (locked state) the phase (or frequency) of the output signal generated by an oscillator with the reference or input signal in phase (or frequency) . Reference Signal generator Phase Detector (P.D) Low Pass Filter (L.P.F) Voltage Controlled Oscillator (V.C.O) Output
Fig 2 :- Circuit diagram of digital phase frequency detector(PFD) Fig 3 :- Circuit diagram of digital phase detector using tanner tools with reference input and VCO output Fig 2 :- Circuit diagram of digital phase frequency detector(PFD) Fig 6 :- Circuit diagram of phase detector Fig 6 :- Circuit diagram of phase detector 6
Fig 3 :- Output waveform of digital phase frequency detector using W-edit
Fig 4 :- Circuit diagram of PLL filter using multisim and input/output waveform 8
Fig 5 :- Circuit diagram of VCO using tank circuit and output waveform 9
Fig 6 :- Circuit diagram of VCO using MOSFETs ( current starved VCO ) 10
Fig 7 - Output response and Simulation result of current starved VCO
Fig 8 :- Circuit diagram of current starved VCO
LINEAR MODEL OF PLL 13 Fig :- 7
Fig 9 :- 14
HOW IT WORKS
Reference Signal Generator Phase Locked Loop Model in Transmitting Section : PLL circuit is designed as frequency synthesizer, which used to generate two different frequencies dependent to control signal – when control bit ‘0’ PLL circuit will generate 100 MHz, when control bit ‘1’ the circuit will generate 100.1MHz. After that the synthesized signal is used as the clock signal of data buffer or First-In First-Out (FIFO) data buffer to drive out the data signal. Reference Signal Generator 10 16
FREQUENCY SYNTHESIZER 11
Fig 12 :- Circuit diagram of FREQUENCY DIVIDER 18
Fig 13 :- Out put waveform of FREQUENCY DIVIDER 19
Phase Locked Loop Model in Receiving Section : The received signal is injected to PLL circuit, at the steady state of PLL system, the clock signal will be recovered from received signal. Low pass filter is used to reject the high frequencies of this signal and then the control signal can be recovered. 14
PLL used for CLOCK RECOVERY 15 21
Fig 14 :- Circuit diagram of EDGE DETECTOR & waveform 22
Fig 15 :- SCHEMATIC DIAGRAM OF PHASE DETECTOR 23
Fig 15 (b):- SCHEMATIC DIAGRAM OF DIGITALPHASE DETECTOR
Fig 16 :- SCHEMATIC DIAGRAM OF ACTIVE 2ND ORDER LOW PASS FILTER 25
Fig 17 :- SCHEMATIC DIAGRAM OF CURRENT STARVED VCO 26
Fig 18 :- SCHEMATIC DIAGRAM OF FREQUENCY DIVIDER 27 27
Fig 19 :- Implementation of PLL in Transmission section 28
Fig 20 :- Schematic diagram of Edge detector 29
Fig 21 :- Implementation of PLL in Receiver section for clock recovery 30
Future Works Hardware implementation of the project to be done. Hardware implementation of the project to be done. Working of the project in GHz range by virtue of which more faster application speed can be achieved. Optimization of VCO in accordance with the increased frequency range to achieve more clarity and faster speed in communication. Improvement of output performance in transmitting and receiving section such as :Lock range, Capture range, Pull in time, Bandwidth of PLL. Noise reduction during the communication by varying the system parameters such as : Jitter, Phase noise ( VCO, PD, Frequency Divider), Reference spur. Implementation of the circuit in various environment such as: Airplanes, High profile cars and buses, Communication sectors in factories etc. to view the proper practical applications and modification accordingly. 31
REFERENCES : [1] Behzad Razavi, “Design of Analog CMOS Integrated Circuits”, Tata-McGraw Hill 2002, Ch. 15, page. 532-576 [2] Swanand Solanke, D. P. Acharya, “Design of Efficient Charge Pump in Phase Locked Loop for Wireless Communication”, National Conference on Emerging Trends in Engineering Technology and Applications, 2009, NCETETA09. [3] “Li-Fi (Light Fidelity)-The Future Technology In Wireless Communication”, International Journal of Applied Engineering Research, ISSN 0973-4562 Vol.7 (2013) [4] Koji Nonaka,Yoshiyuki Isobe, High Speed Optical Wireless Access with VCSELArray Beam Micro-cell System. [5] Vemceslav F.Kroupa, Phase Locked Loops and Frequency Synthesis, John Wiley&Sons Ltd, 2003. [6] Behzad Razavi, Monolithic Phase-Locked Loops and Clock Recovery Circuits, Wiley - Interscience, 2006. [7] “PLL design for optical fiber li-fi” by Ampornrat Posri , February 2005 [8] Dan H. Wolaver, Phased-Locked Loop Circuit Design, Prentice Hall, 1991. [9] Floy M.Gardner, Charge-Pump Phase Locked Loops, IEEE,Trans. November 2010. [10] Wogeun Ree, “Design of High Performance CMOS Charge Pumps in Phase Locked Loop”, IEEE International Symposium on Circuits and Systems ISCAS`99, vol. 2, June 2011. 32