In this paper we address the problem of channel estimation for Multiple-Input Multiple-Output OFDM systems for mobile users. Channel tracking and equalization method stemming from Kalman filtering is proposed for time-frequency selective channels. Tracking of MIMO channel matrix is performed in time-domain and equalization in frequency domain. Computational complexity is significantly reduced b...

Abstract A possible problem of orthogonal frequency division multiplexing (OFDM) is its high peak-to-average power ratio (PAPR). Recently, the single carrier (SC) transmission system with frequency-domain equalization is attracting much attention. In this paper, a novel approach to alleviate the PAPR problem of OFDM is proposed. A generalized OFDM (GOFDM) with frequency-domain equalization is p...

Similar to the single-carrier transmission [1], the bit error rate (BER) performance of DS-CDMA in a frequency-selective fading channel can be significantly improved with coherent frequency-domain equalization (FDE) instead of using Rake combining [2][3]. However, coherent FDE requires accurate channel estimation and the imperfect channel estimation results in the performance degradation. For p...

Abstract Recently, the frequency-domain equalization (FDE) has been attracting much attention since it is an effective equalization technique for direct-sequence code division multiple access (DS-CDMA) signal transmission in a frequency-selective fading channel. In practical systems, the square-root Nyquist transmit and receive filters are used for the bandwidth limitation of the transmitted si...

Abstract DS-CDMA with frequency domain minimum mean square error (MMSE) equalization can provide much better performance than that with rake combining in a frequency selective fading channel. Chip interleaving is a form of channel interleaving that improves the DS-CDMA performance by converting the channel into a highly time selective channel. When frequency domain equalization is used, the fre...

In this paper, we propose a novel iterative transmit/receive equalization technique for single-carrier (SC) block transmission in a severe frequency-selective fading channel. Iterative frequency-domain intersymbol interference (ISI) cancellation (FDIC) is introduced to the previously proposed joint iterative transmit/receive frequency-domain equalization (FDE) based on the minimum mean square e...

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide a better bit error rate (BER) performance than rake combining. To further improve the BER performance, cyclic delay transmit diversity (CDTD) can be used. CDTD simultaneously transmits the same signal from different antennas after adding different cyclic delays to increase the number of equiv...

This paper focuses on Multiple-Input MultipleOutput (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems, where the MIMO channel order is larger than the length of the Cyclic Prefix (CP). By swapping the filtering operations of the MIMO channel and the Fast Fourier Transform (FFT), it is shown that each tone of a MIMO OFDM system can be viewed as a MIMO Single-Carrier (SC) system. A...