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—Zero padding (ZP) of multicarrier transmissions has recently been proposed as an appealing alternative to the traditional cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM) to ensure symbol recovery regardless of the channel zero locations. In this paper, both systems are studied to delineate their relative merits in wireless systems(More)
—This paper proposes a new blind channel estimation method for orthogonal frequency division multiplexing (OFDM) systems. The algorithm makes use of the redundancy introduced by the cyclic prefix to identify the channel based on a subspace approach. Thus, the proposed method does not require any modification of the transmitter and applies to most existing(More)
—Space time coding has by now been well documented as an attractive means of achieving high data rate transmissions with diversity and coding gains, provided that the underlying propagation channels can be accounted for. In this paper, we rely on redundant linear precoding to develop a (semi-)blind channel estimation algorithm for space time (ST) orthogonal(More)
The widespread application of OFDM for local area mobile wireless broadband systems is strongly motivated by the simple equalization it aaords. OFDM's bottleneck of channel-dependent performance was only recently addressed by replacing the cyclic preex (CP) with trailing zeros (TZ). Such zero-padded OFDM transmissions enable FIR channel-irrespective symbol(More)
The effects of uniform spreading in OFDM-CDMA systems is the harmonization at the reception of the Signal to Noise Ratio between the sub-bands which prevents the good performance of Successive Decoding algorithms. This paper proposes a new Hybrid Spread OFDM (SOFDM) transmission scheme in which the spreading of the information is adjustable and not uniform(More)
A new subspace method performing the blind and semi-blind identification of the transmission channel suited to multicarrier systems with cyclic prefix (OFDM) is proposed in this paper. This technique has the advantage to preserve the classical OFDM emit-ter structure based on a cyclic prefix insertion. Therefore it applies to all existing standardized(More)
In this paper two new blind channel identification methods suited to mul-ticarrier system (OFDM) exploiting the redundancy introduced by the adjunction of a cyclic prefix at the emitter and relying on the evaluation of the received signal autocorrelation matrix are presented. The proposed algorithms are able to identify any channel without any constraint on(More)
Mobile WiMAX systems are based on the IEEE 802.16e specifications, which include two mandatory MIMO profiles for the downlink. One of these is Alamouti's space-time code (STC) for transmit diversity, and the other is a 2times2 spatial multiplexing MIMO scheme. In this paper, we compare the two schemes assuming that the latter employs maximum-likelihood(More)
—This letter extends turbo-demodulation to the zero-padded OFDM (ZP-OFDM) system by accounting for the noise color and the symbols estimates correlation introduced by equalization. Resorting to realistic simulations, we show that turbo-demodulation used with set partitioning labeling can significantly outperform noniterative decoding with Gray labeling. We(More)