Potential Future Work

In this thesis, our main goal is implement the DL system on the DSP platform. And we have been optimized the inefficient functions, but the synchronization function is still complex. The bottleneck of synchronization function is the pilot correlation.

This is because that we have to do 65 times of FFT in initial synchronization or 33 times of FFT in tracking mode. Although the shift-FFT[2] have been used to reduce the computational complexity, the computation of FFT is still a huge loading in synchronization. Besides complexity, we still find that the pilot correlation function may search the wrong symbol time even without adding noise and channel. If we will modify the synchronization algorithm, we suggest that we can modify the frame synchronization algorithm first for this reason. In IEEE Std 802.16-2004, the preamble is allocated in front of the DL subframe and it may help us to improve frame synchronization algorithm.

To fulfill the real time requirement, we can still make more effort on the program.

We may notice the coding style to prevent the waste of the computation unnecessary or use intrinsics to accelerate the program. One another way is skipping a function call when it is idle operation. But we may notice that if we adopt this method, it may make lots of conditionals in the program and then make the compiler hard to do the optimization. The tradeoff should be estimated carefully.

In our DSP program, we do not implement FEC encoder/decoder yet. We can find the associated reference in [5].

Bibliography

[1] M.-T. Lin, “Fixed and mobile wireless communication based on IEEE 802.16a TDD OFDMA: transmission filtering and synchronization,” M.S. thesis, De-partment of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan, R.O.C., June 2003.

[2] T.-S. Chiang, “Study and DSP implementation of IEEE 802.16a TDD OFDM downlink synchronization,” M.S. thesis, Department of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan, R.O.C., July 2004.

[3] IEEE Std 802.16a-2003, IEEE Standard for Local and Metropolitan Area Net-works — Part 16: Air Interface for Fixed Broadband Wireless Access Systems

— Amendment 2: Medium Access Control Modifications and Additional Phys-ical Layer Specifications for 2–11GHz. New York: IEEE, Apr. 1, 2003.

[4] IEEE Std 802.16-2004, IEEE Standard for Local and Metropolitan Area Net-works — Part 16: Air Interface for Fixed Broadband Wireless Access Systems.

New York: IEEE, Oct. 1, 2004.

[5] C.-C. Tung, “IEEE 802.16a OFDMA TDD uplink transceiver tystem integra-tion and optimizaintegra-tion on DSP platform,” M.S. thesis, Department of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan, R.O.C., June 2005.

[6] R.-C. Chen, “Techniques for and DSP software implementation of IEEE 802.16a TDD OFDMA downlink pilot-aided channel estimation,” M.S. thesis, Depart-ment of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan, R.O.C., Juue 2005.

[7] J. J. van de Beek et al., “ML estimation of time and frequency offset in OFDM systems,” IEEE Trans. Signal Processing, vol. 45, no. 7, pp. 1800–1805, July 1997.

[8] J. J. van de Beek, P. O. Borjesson, M. L. Boucheret, D. Landstrom, J. M.

Arenas, P. Odling, C. Ostberg, M. Wahlqvist, and S. K. Wilson, “A time and frequency synchronization scheme for multiuser OFDM,” IEEE J. Select. Areas Commun., vol. 17, pp. 1900–1914, Nov. 1999.

[9] P. H. Moose, “A technique for orthogonal frequency-division multiplexing fre-quency offset correction,” IEEE Trans. Commun., vol. 42, no. 10, pp. 2908–

2914, Oct. 1994.

[10] C. D. Murphy, “Low-complexity FFT structure for OFDM transceivers,” IEEE Trans. Commun., vol. 50, no. 12, pp. 1878–1881, Dec. 2002.

[11] H. V. Sorenson, C. S. Burrus, “Efficient computation of the DFT with only a subset of input or output points,” IEEE Trans. Signal Processing, vol. 41, no.

3, pp. 1184–1200, Mar. 1993.

[12] J. D. Markel, “FFT pruning,” IEEE Trans. Audio Electroacoust., vol. AU-19, no. 4, pp. 305–311, Dec. 1971.

[13] G. Goertzel, “An algorithm for the evaluation of finite trigonometric series,”

Amer. Math. Monthly, vol. 65, no. 1, pp. 34–35, Jan. 1958.

[14] ETSI SMG, “Overall requirements on the radio interface(s) of the UMTS,”

Technical Report ETR/SMG-21.02, v.3.0.0., ETSI, Valbonne, France, 1997.

[15] Innovative Integration, Quixote User’s Manual, June 2004.

[16] Texas Instruments, Code Composer Studio User’s Guide. Literature number SPRU328B, Feb. 2000.

[17] Texas Instruments, TMS320C64x Technical Overview. Literature number SPRU395B, Jan. 2001.

[18] Texas Instruments, TMS320C6000 DSP Peripherals Overviews Reference Guide. Literature number SPRU190F, Apr. 2004.

[19] Texas Instruments, TMS320C6000 DSP Cache User’s Guide. Literature num-ber SPRU656A, May 2003.

[20] Texas Instruments, TMS320C6000 CPU and Instruction Set. Literature num-ber SPRU189F, Oct. 2000.

[21] Texas Instruments, TMS320C6000 Programmer’s Guide. Literature number SPRU198G, Oct. 2002.

[22] Texas Instruments, TMS320C64x DSP Library Programmer’s Reference. Liter-ature number SPRU565B, Oct. 2003.

[23] Innovative Integration, Quixote Data Sheet, http://www.innovative-dsp.com/support/datasheets/quixote.pdf.

[24] IEEE 802.16 Working Group, IEEE 802.16 Working Group Website, http://www.ieee802.org/16/.

[25] The Code Project, The Code Project Website,

http://www.codeproject.com/miscctrl/graph2d.asp.

[26] Texas Instruments, TMS320C6000 Code Composer Studio Getting Started Guide. Literature number SPRU509D, Aug. 2003.

自傳

陳昱昇，男，民國七十年一月二十五日出生於台灣省桃園縣。高中 就讀於桃園武陵高中，民國 92 年六月畢業於交通大學電子工程學 系，並於九月進入交通大學電子工程研究所繼續就讀，於民國 94 年 取得碩士學位，論文題目為:『IEEE 802.16a 分時雙工正交分頻多重 進接下行傳收系統之數位訊號處理器軟體實現與整合』，是有關無線 通訊領域的相關研究。

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