Adaptive loading based on frequency-selective fading estimation for ultra high-data-rate OFDM system

In the frequency-selective fading environments, the error probability performance of orthogonal frequency division multiplexing (OFDM) is severely degraded by the subcarriers where the deep fading occurs. The frequency-domain adaptive bit and power loading is a very effective method to improve this situation. However, it is not always useful, e.g., in the frequency-flat fading scenarios, its performance gain over the fixed loading may shrink or even disappear. In order to deal with this issue, we propose an adaptive loading scheme which is based on the estimation of the frequency-selective fading severity. This scheme is tested based on an ultra high-data-rate OFDM system which is capable of supporting beyond 100 Mbps data rate transmission in the air interface. The numerical analysis results show that it is very necessary to employ such an adaptive loading scheme to broad-band OFDM system in the scenarios where both the frequency-selective and frequency-flat fading may be encountered.

[1]  David Tse,et al.  Asymptotically optimal water-filling in vector multiple-access channels , 2001, IEEE Trans. Inf. Theory.

[2]  John M. Cioffi,et al.  A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels , 1995, IEEE Trans. Commun..

[3]  A. Czylwik,et al.  Adaptive OFDM for wideband radio channels , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[4]  Paul J.M. Havinga,et al.  MIRAI architecture for heterogeneous network , 2002, IEEE Commun. Mag..

[5]  Satoshi Takahashi,et al.  Dynamic parameter controlled orthogonal frequency and time division multiple access , 2004, 2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications (IEEE Cat. No.04TH8754).

[6]  H. Harada.  100 Mbps and beyond point-to-multipoint ultra high-speed radio access system: concept and fundamental experimental results , 2003, 2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484).

[7]  L. Hanzo,et al.  Adaptive multicarrier modulation: a convenient framework for time-frequency processing in wireless communications , 2000, Proceedings of the IEEE.

[8]  Lajos Hanzo,et al.  Adaptive modulation techniques for duplex OFDM transmission , 2000, IEEE Trans. Veh. Technol..

[9]  迪克·胡斯·哈托格斯.  Ensemble modem structure for imperfect transmission media , 1986 .

[10]  Robert F. H. Fischer,et al.  A new loading algorithm for discrete multitone transmission , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.