Similar articles

Abstract: This paper proposes a novel LDPC based differential unitary space-frequency coding (DUSFC) scheme for MIMO-OFDM systems when neither the transmitter nor the receiver has access to the channel state information (CSI). The new DUSFC strategy basically consists of coding across transmit antennas and OFDM tones simultaneously as well as differential modulation in the time-domain. It can fully exploit the inherent advantages provided by the multipath fading channels, resulting in a high degree of diversity. The state-of-the-art low-density parity-check (LDPC) codes are concatenated with our DUSFC as channel coding to improve the bit error rate (BER) performance considerably. Owing to the maximum multipath diversity and large coding advantages, LDPC-DUSFC strongly outperforms the differential unitary space-time coded OFDM techniques recently proposed in literature. The corresponding iterative decoding algorithm without channel estimation is finally provided to offer significant performance gain. Simulation results illustrate the merits of the proposed scheme.

[1] Boelcskei, H., Paulraj, A.J., 2000. Space-Frequency Coded Broadband OFDM Systems. Proc. IEEE Wireless Commun. Network Conf., p.1-6.

[2] Gallager, R.G., 1962. Low density parity check codes. IRE Trans. Inform. Theory, IT-8:21-28.

[3] Hochwald, B.M., Marzetta, T.L., 2000. Unitary space-time modulation for multiple antenna communication in Rayleigh flat-fading. IEEE Trans. Inform. Theory, 46:543-564.

[4] Hochwald, B.M., Sweldens, W., 2000. Differential unitary space-time modulation. IEEE Trans. on Comm., 48(12):2041-2052.

[5] Kou, Y., Lin, S., Fossorier, M.P.C., 2001. Low-density parity-check codes based on finite geometries: a rediscovery and new results. IEEE Trans. Inform. Theory, 47(7):2711-2736.

[6] Liu, Z., Giannakis, G.B., Hughs, B.L., 2001. Double differential space-time block coding for time-selective fading channels. IEEE Trans. Comm., 49:1529-1539.

[7] Liu, Z., Xin, Y., Giannakis, G.B., 2002. Space-time-frequency block coded OFDM with subcarrier grouping and constellation precoding. IEEE ICASSP’02, 3:2205-2208.

[8] Mackay, D.J.C., 1999. Good err-correcting codes based on very sparse matrices. IEEE Trans. Inform. Theory, 45:399-432.

[9] Mackay, D.J.C., Neal, R.M., 1996. Near Shannon limit performance of low density parity check codes. Electron. Lett., 32(18):1645-1646.

[10] Sun, Y., Xiong, Z., Wang, X., 2002. Scalable image transmission over differentially space-time coded OFDM systems. IEEE GLOBECOM’02, 1:379-383.

[11] Tarokh, V., Seshadri, N., Calderbank, A.R., 1998. Space-time codes for high data rate wireless communication: Performance criterion and code construction. IEEE Trans. Inform. Theory, 44(2):744-765.