Minimum-mean-output-energy blind adaptive channel shortening for multicarrier SIMO transceivers

In this paper, we propose a blind adaptive channel shortening method for designing finite-impulse response time-domain equalizers (TEQs) in single-input multiple-output (SIMO) systems employing multicarrier modulations. The proposed algorithm, which relies on a constrained minimization of the mean-output-energy at the TEQ output, does not require neither a priori knowledge of the channel impulse response nor transmission of training sequences, and admits an effective and computationally-efficient adaptive implementation. Moreover, the proposed TEQ is narrowband-interference resistant and its synthesis only requires an upper bound (rather than the exact knowledge) of the channel order. Numerical simulations are provided to illustrate the advantages of the proposed technique over a recently developed blind channel shortener

Cooperative randomized MIMO-OFDM downlink formulticell networks: design and analysis

This paper proposes a low-complexity physical (PHY) layer design to introduce cooperation in the downlink of an infrastructure-based multicell multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) network, aimed at supporting future high-throughput broadband wireless Internet access with large-scale coverage. In such a system, several multi-antenna base stations (BSs) are organized in a cellular architecture to serve multiantenna mobile stations (MSs) and are connected to a central service unit via a high-speed wired backbone. To improve the network performance, a novel PHY layer design is proposed that allows cooperation among an arbitrary and unknown number of BSs, by suitably randomizing the MIMO-OFDM block codes used by the BSs. Such a randomized MIMO-OFDM code renders the encoding/decoding rule independent of the number of actual BSs cooperating and works without any channel feedback, which greatly simplifies the protocol as well as the MS design. To provide performance insights and develop PHY layer designs, the paper provides analytical upper bounds on the symbol error probability for linear receivers, which allow to accurately evaluate the diversity order and the coding gain achievable through the proposed scheme. Finally, we present numerical results that validate the theory and highlight the performance gain and the coverage expansion attainable with our cooperative transceiver