In this paper, and for the first time, the performance of various ultra wideband pulse modulation schemes are discussed and compared in terms of narrowband interference robustness, symbol error rate, system complexity, data rate, and maximum transmit power with respect to transceiver distance and channel capacity. The channel model is the UWB IEEE 802.15.3a multipath indoor channel model under additive white Gaussian noise. The transmit power was evaluated by integrating the fifth derivative of the power spectrum density of the Gaussian pulse over the whole bandwidth. 1. Introduction In ultra wideband (UWB) system design, there are always tradeoffs between maximum transmit distance, data rate, transmit power, and system complexity. Different data modulation schemes such as pulse-position modulation (PPM), pulse-amplitude modulation (PAM), phase-shift keying (PSK), or on-off keying (OOK) have been used in UWB communications with relative success depending on the targeted application [1, 2]. In fact, their performance can significantly vary according to which system parameters are considered such as narrowband interference (NBI) robustness, symbol error rate (SER), system complexity, data rate, or maximum transmit power with respect to transceiver distance and channel capacity. For instance, if minimum complexity is important, then OOK modulation would be the best choice. However, it is very sensitive to noise. On the other side, if interference robustness and power efficiency are the parameters to consider, binary PSK (BPSK) and M-ary PPM (M-PPM) can be the best candidates. Nevertheless, M-PPM deals with multidimensional signals, whereas M-PAM has only one dimension [3, 4]. This topic has been widely discussed in the last decade but most of published works [4] did not efficiently include all tradeoffs, such as comparison of bit error rate (BER), modulation level, channel capacity, and complexity. In fact, even if several technical papers have already discussed this issue, they mainly investigated the modulation performance for specific applications or system requirements and thus, to the best of our knowledge, did not cover the whole comparison spectrum [5]. The objective of this paper is indeed to evaluate all these parameters and their impact on each scheme performance. For this aim, we considered the PPM in time-hopping mode (TH-mode), the OOK in direct-sequence mode (DS-mode), and the binary PAM (BPAM) in both TH- and DS-modes. The channel model is the UWB IEEE 802.15.3a indoor channel model under additive white Gaussian noise (AWGN) [6]. Note that
References
[1]
A. Naanaa and S. Belghith, “Performance enhancement of a time hopping—pulse position modulation ultra-wideband system using guided local search,” IET Journal of Communications, vol. 5, no. 15, pp. 2212–2220, 2011.
[2]
Q. Zhu, Z. Jia, and C. Zou, “On the performance of different modulation schemes for UWB systems in a multipath channel,” in Proceedings of the IET International Conference on Wireless, Mobile and Multimedia Networks, pp. 1–4, November 2006.
[3]
R. Hidayat and Y. Miyanaga, “IR-UWB pulse position modulation and pulse shape modulation through S-V channel model,” in Proceedings of the 2nd International Conference on Communication Software and Networks (ICCSN '10), pp. 214–217, February 2010.
[4]
A. Al Zaman and N. Islam, “Modulation schemes and pulse shaping in ultra wideband,” in Proceedings of the IEEE Southeast conference, pp. 142–146, April 2008.
[5]
C. Ngo and D. Birru, “Analysis of UWB modulation techniques,” in Proceedings of the International Conference on Wireless Networks (ICWN '03), pp. 646–652, June 2003.
[6]
M. G. Di Benedetto and G. Giancola, Understanding Ultra Wide Band Radio Fundamentals, Prentice Hall, New York, NY, USA, 2004.
[7]
M. Ghavami, L. B. Michael, R. Kohno, and U. W. B. Signals a, Systems in Communication Engineering, John Wiley & Sons, New York, NY, USA, 2nd edition, 2007.
[8]
H. Sheng, “On the spectral and power requirements for ultra-wideband transmission,” in Proceedings of the International Conference on Communications (ICC '03), pp. 738–742, May 2003.
[9]
L. Ma and T. C. Wang, “Performance analysis and simulations of UWB-PAM communications in AWGN channel,” in Proceedings of the 4th International Conference on Microwave and Millimeter Wave Technology (ICMMT '04), pp. 830–833, August 2004.
[10]
Z. Ye, “Power spectral density and in-band interference power of UWB signals at narrowband systems,” in Proceedings of the IEEE International Conference on Communications, pp. 3561–3565, June 2004.
[11]
J. Nielsen and S. Zwierzchowski, “Power spectral density of a UWB signal with discrete quantized pulse positions,” Canadian Journal of Electrical and Computer Engineering, vol. 28, no. 3-4, pp. 145–154, 2003.
[12]
P. E. McIllree, “Calculation of channel capacity for M-ary digital modulation signal sets,” in Proceedings of the IEEE Singapore International Conference on Networks, pp. 639–643, Singapore, September 1993.
[13]
S. S. Mo, “On the power spectral density of UWB signals in IEEE 802.15.3a,” in Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC '04), pp. 999–1003, March 2004.
[14]
L. Zhao and A. M. Haimovich, “Capacity of M-ary PPM ultra-wideband communications over AWGN channels,” in Proceedings of the IEEE 54th Vehicular Technology Conference (VTC FALL '01), pp. 1191–1195, October 2001.
[15]
R. Pasand, “Capacity of PPM ultra-wideband communications with inter pulse interference,” in Proceedings of the Canadian Conference on Electrical and Computer Engineering, pp. 2355–2358, May 2004.
[16]
V. Somayazulu, J. R. Foerster, and S. Roy, “Design challenges for very high data rate UWB systems,” in Proceedings of the 36th Asilomar Conference on Signals Systems and Computers, pp. 717–721, November 2002.
