FPGA implementation of digital timing recovery in software radio receiver

This paper describes an implementation of an all-digital timing recovery scheme. Squaring nonlinearity is employed to generate the timing estimate and an IIR is used to extract the spectral component at symbol rate. Hardware design is performed using VHDL and realized in FPGA. The whole design can be fitted into an Altera EPF1OK70 FPGA chip, with 95.5% utilization of logic elements and 22% utilization of memory bits. The implementation exploits features of FPGA, which enable easy implementation of look up table and variable data precision at different nodes.

[1]  Lars Erup,et al.  Interpolation in digital modems. II. Implementation and performance , 1993, IEEE Trans. Commun..

[2]  C. W. Farrow,et al.  A continuously variable digital delay element , 1988, 1988., IEEE International Symposium on Circuits and Systems.

[3]  F. Gardner Interpolation in Digital Modems-Part I: Fundamentals , 2000 .

[4]  Heinrich Meyr,et al.  Digital filter and square timing recovery , 1988, IEEE Trans. Commun..

[5]  Alan V. Oppenheim,et al.  Discrete-Time Signal Pro-cessing , 1989 .

[6]  Hyeong-Sook Park,et al.  The implementation of modulator using FPGA technology for W-CDMA WLL , 1997, Proceedings. Tenth Annual IEEE International ASIC Conference and Exhibit (Cat. No.97TH8334).

[7]  Jun Mo Koo,et al.  A wideband DS-CDMA modem for a mobile station , 1999, IEEE Trans. Consumer Electron..

[8]  Floyd M. Gardner,et al.  Interpolation in digital modems. I. Fundamentals , 1993, IEEE Trans. Commun..

[9]  Erup Interpolation in Digital Modems-Part 11 : Implementation and Performance , 2000 .

[10]  D. Al-Khalili,et al.  A high performance, wide bandwidth, low cost FPGA-based quadrature demodulator , 1999, Engineering Solutions for the Next Millennium. 1999 IEEE Canadian Conference on Electrical and Computer Engineering (Cat. No.99TH8411).