1,246 research outputs found

    Sparse Reconstruction-based Detection of Spatial Dimension Holes in Cognitive Radio Networks

    Full text link
    In this paper, we investigate a spectrum sensing algorithm for detecting spatial dimension holes in Multiple Inputs Multiple Outputs (MIMO) transmissions for OFDM systems using Compressive Sensing (CS) tools. This extends the energy detector to allow for detecting transmission opportunities even if the band is already energy filled. We show that the task described above is not performed efficiently by regular MIMO decoders (such as MMSE decoder) due to possible sparsity in the transmit signal. Since CS reconstruction tools take into account the sparsity order of the signal, they are more efficient in detecting the activity of the users. Building on successful activity detection by the CS detector, we show that the use of a CS-aided MMSE decoders yields better performance rather than using either CS-based or MMSE decoders separately. Simulations are conducted to verify the gains from using CS detector for Primary user activity detection and the performance gain in using CS-aided MMSE decoders for decoding the PU information for future relaying.Comment: accepted for PIMRC 201

    Damped Zero-Pseudorandom Noise OFDM Systems

    Get PDF
    This paper proposed a new OFDM scheme called damped zero-pseudorandom noise orthogonal frequency division multiplexing (DZPN-OFDM) scheme. In the proposed scheme, ZPN-OFDM non-zero part damped to reduce the guard interval energy as well as the mutual interference power in-between the data and training blocks, and conservative the pseudo-noise conventional properties required for channel estimation or synchronization. The motivation of this paper is the OFDM long guard interval working in wide dispersion channels, where significant energy waste if conventional ZPN-OFDM is used as well as the BER performance degradation. Also, to solve the ZPN-OFDM spectrum efficiency loss problem, the proposed scheme doesn’t duplicate the guard interval. Both detailed performance analysis and simulation results show that the proposed DZPN-OFDM scheme can, indeed, offer significant bit error rate, spectrum efficiency as well as energy efficiency improvement

    D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking

    Get PDF
    Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the various Joint Research Activities (JRA) in WP1.3 and the results that were developed up to the second year of the project. For each activity there is a description, an illustration of the adherence to and relevance with the identified fundamental open issues, a short presentation of the main results, and a roadmap for the future joint research. In the Annex, for each JRA, the main technical details on specific scientific activities are described in detail.Peer ReviewedPostprint (published version
    corecore