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Efficient Use of Application Specific CORDIC for Digital Demodulation in I/Q Receiver

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Abstract (2. Language): 
Digital modalities of sine and cosine waves are gaining enormous attention in the field of vector rotated Digital Signal Processing (DSP) applications. COordinate Rotation DIgital Computer (CORDIC) algorithm has become very important and widely researched topic due to its simplicity to cater almost perfect digital sine and cosine waveforms during modulation and demodulation processes in various digital designs. In DSP applications, the quantization errors generated in CORDIC may propagate through subsequent modules ending up with reduced SNR of the system as a whole. In this paper, we have presented the design of a pipelined CORDIC architecture for detection of amplitude- phase variations in a demodulator of FMCW radar. The angle approximation and rounding off error of CORDIC have been intensively studied for the determination of design parameters. An expression for overall quantization error is derived. The design of application specific CORDIC processor in the circular rotation mode gives a high system throughput due to its pipelined architecture by reducing latency in each individual pipelined stage. Saving area on FPGA is essential to the design of pipelined CORDIC and that can be achieved through the optimization in the number of micro rotations. Hardware synthesized result using Cadence design tools are presented.
FULL TEXT (PDF): 
1581-1587

REFERENCES

References: 

[1] J. E. Volder, "The CORDIC Trigonometric Computing
Technique", IRE Transactions on Electronic Computing, vol.
EC-8, pp. 330-334, Sept, 1959.
[2] Y. H. Hu, "CORDIC-Based VLSI Architectures for Digital
Signal Processing", IEEE Signal Processing Magazine, vol.
9, no. 3, pp. 16-35, 1992.
[3] S. Aggarwal, P. K. Meher, K. Khare, "Area-Time Efficient
Scaling-Free CORDIC Using Generalized Micro-Rotation
Selection", IEEE Transactions on VLSI System, vol. 20, no. 8,
pp. 1542-1546, Aug, 2012.
[4] S. Ugazio, "Design of real time adaptive DPLLs for generic
and variable Doppler frequency", in International Conference
on Localization and GNNS (ICL-GNSS)”, pp. 169-174,
Tampere, Jun, 2011.
[5] B. K. Kang, H. J. Kwon, B. K. Mheen, H. –J. Yoo and Y. H.
Kim, "Nonlinearity Compensation Circuit for voltagecontrolled
oscillator operating in linear frequency sweep
Cells Leakage
Power
(nW)
Dynamic
Power
(μW)
Total
Power
(μW)
95 112.132 112.64 112.752
0 20 40 60 80 100 120 140 160 180 200
-1
-0.5
0
0.5
1
1.5
Phase-Amplitude Variations
Iterations
Real part of Radar Echo Vs. COHO
Radar Echo
Reference COHO Signal
0 20 40 60 80 100 120 140 160 180 200
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Demodulator Output
Iterations
Types Instances
Area Area %
Sequentials 59 3941.784 89.0
Inverter 1 6.653 0.2
Logic 35 479.002 10.8
Total 95 4427.438 100.0
0 20 40 60 80 100 120 140 160 180 200
-1
-0.5
0
0.5
1
1.5
Embeded Signal with Phase Shift
Iterations
A. Mandal and R. Mishra / IU-JEEE Vol. 13(1), (2013), 1581-1587
1587
mode", IEEE Microwave and Guided Wave Letters, vol. 10, no. 12, pp. 537-539, Dec 2000.
[6] K. Kota, J. R. Cavallaro, "Numerical accuracy and hardware trade-offs for CORDIC arithmetic for special purpose processors", IEEE Transactions on Comuters, vol. 42, no. 7, pp. 769-779, Jul 93.
[7] Y. H. Hu, "The Quantization Effects of the CORDIC Algorithm", IEEE Transactions on signal processing, vol. 40, no. 4, pp. 834-844, Apr 1992.
[8] T. –Y. SUNG, H. –C. HSIN, "Fixed-Point Error Analysis of CORDIC Arithmetic for Special-Purpose Signal Processors", IEICE Trans. Fundamentals, vol. E90-A, no. 9, Sept 2007.
[9] A. Banerjee, A. S. Dhar, "Pipelined VLSI Architecture using CORDIC for Transform Domain Equalizer", journal of signal Processing systems, vol. 70, pp. 39-48, 2013.
[10] J. Vuori, "Implementation of a Digital Phase-Locked Loop Using CORDIC Algorithm", IEEE International Symposium on Circuits and Systems, vol. 4, pp. 164-167, Atlanta, 1996.
[11] W. Xu, C. Gu, C. Li, M. Sarrafzadeh, "Robust Doppler radar demodulation via compressed sensing", Electronics Letters, vol. 48, no. 22, pp. 1428-1430, Oct, 2012.
[12] B. R. Mahafza, A. Elsherbeni, "MATLAB Simulations for Radar Systems Design", CRC, Florida, USA, 2003.

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