Now showing items 1-22 of 22

  • High-Throughput Multi-rate LDPC Decoder based on Architecture-Oriented Parity Check Matrices 

    Radosavljevic, Predrag; de Baynast, Alexandre; Karkooti, Marjan; Cavallaro, Joseph R. (2006-09-01)
    A high throughput pipelined LDPC decoder that supports multiple code rates and codeword sizes is proposed. In order to increase memory throughput, irregular block structured parity-check matrices are designed with the ...
  • Multi-Rate High-Throughput LDPC Decoder: Tradeoff Analysis between Decoding Throughput and Area 

    Radosavljevic, Predrag; de Baynast, Alexandre; Karkooti, Marjan; Cavallaro, Joseph R. (2006-09-01)
    In order to achieve high decoding throughput (hundreds of MBits/sec and above) for multiple code rates and moderate codeword lengths (up to 2.5K bits), several decoder solutions with different levels of processing parallelism ...
  • Half-Duplex Estimate-and-Forward Relaying: Bounds and Code Design 

    Chakrabarti, Arnab; de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2006-07-01)
    We propose a coding scheme for half-duplex estimate-and-forward relaying. Our first contribution is to present an achievable rate for the estimate-and-forward protocol. We also derive the achievable rate for the special ...
  • LDPC Code-Design for the Relay Channel 

    Chakrabarti, Arnab; de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2006-06-01)
    We propose LDPC code designs for the half-duplex relay channel. Our designs are derived from the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it ...
  • LDPC Code Design for Relay Channel in Time-Division mode 

    de Baynast, Alexandre; Chakrabarti, Arnab; Sabharwal, Ashutosh; Aazhang, Behnaam (2006-06-01)
    We address the problem of LDPC code design for relay channel in time-division mode based on a distributed strategy: In the first time slot, the source transmits part of the codeword. The relay and the destination receive ...
  • On Turbo-Schedules for LDPC Decoding 

    de Baynast, Alexandre; Radosavljevic, Predrag; Sabharwal, Ashutosh; Cavallaro, Joseph R. (2006-05-01)
    The convergence rate of LDPC decoding is comparatively slower than turbo code decoding: 25 LDPC iterations versus 8-10 iterations for turbo codes. Recently, Mansour proposed a â turbo-scheduleâ to improve the convergence rate ...
  • Performance of Multi Binary Turbo-Codes on Nakagami Flat Fading Channels 

    de Baynast, Alexandre (2006-05-01)
    In this paper, performance in terms of Bit Error Rate (BER) and Frame Error Rate (FER) of multi binary turbo codes (MBTC) over Nakagami frequency nonselective fading channels are presented. The proposed MBTCs consist of ...
  • LDPC Code-Design for the Relay Channel 

    Chakrabarti, Arnab; de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2006-02-01)
    We propose LDPC code designs for the half-duplex relay channel. Our designs are derived from the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it ...
  • High-Throughput Multi-rate LDPC Decoder based on Architecture-Oriented Parity-Check Matrices 

    Radosavljevic, Predrag; de Baynast, Alexandre; Karkooti, Marjan; Cavallaro, Joseph R. (2006-02-01)
    High throughput pipelined LDPC decoder that supports multiple code rates and codeword sizes is proposed. In order to increase memory throughput, irregular block structured parity-check matrices are designed with the ...
  • Half-Duplex Estimate-and-Forward Relaying:Bounds and Code Design 

    Chakrabarti, Arnab; de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2006-01-01)
    We propose a coding scheme for half-duplex estimate-and-forward relaying. Our first contribution is to present an achievable rate for the estimate-and-forward protocol. We also derive the achievable rate for the special ...
  • Analysis of Decision-Feedback Based Broadband OFDM Systems 

    de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2005-11-01)
    In wireless communications, about 25% of the bandwidth is dedicated to training symbols for channel estimation. By using a semi-blind approach, the training sequence length can be reduced while improving performance. The ...
  • Performance of Turbo-Codes on Nakagami Flat Fading (Radio) Transmission Channels 

    de Baynast, Alexandre (2005-11-01)
    The performance in terms of Bit Error Rate and Frame Error Rate for a turbo-coded system in Nakagami frequency-nonselective (flat) fading multipaths channels are presented. An efficient method for generating Nakagami- m ...
  • Optimized Message Passing Schedules for LDPC Decoding 

    Radosavljevic, Predrag; de Baynast, Alexandre; Cavallaro, Joseph R. (2005-11-01)
    The major drawback of the LDPC codes versus the turbo-codes is their comparative low convergence speed: 25-30 iterations vs. 8-10 iterations for turbo-codes. Recently, Hocevar showed by simulations that the convergence ...
  • Optimized Message Passing Schedules for LDPC Decoding 

    Radosavljevic, Predrag; de Baynast, Alexandre; Cavallaro, Joseph R. (2005-11-01)
    The major drawback of the LDPC codes versus the turbo-codes is their comparative low convergence speed: 25-30 iterations vs. 8-10 iterations for turbo-codes. Recently, Hocevar showed by simulations that the convergence ...
  • LDPC Code Design for Half-Duplex Decode-and-Forward Relaying 

    Chakrabarti, Arnab; de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2005-09-01)
    We propose LDPC code designs for the half-duplex relay channel. Our designs mimic the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it is built ...
  • LDPC Code Design for OFDM Channel: Graph Connectivity and Information Bits Positioning 

    de Baynast, Alexandre; Sabharwal, Ashutosh; Aazhang, Behnaam (2005-07-01)
    We present an optimized channel coding scheme for OFDM transmission. In the future wireless standards such IEEE 802.11n, frame error rates (FER) as low as 0.0001 are targeting. Irregular LDPC codes have excellent performance ...
  • Reconfigurable Architectures for Wireless Systems: Design Exploration and Integration Challenges 

    Cavallaro, Joseph R.; Brogioli, Michael C.; de Baynast, Alexandre; Radosavljevic, Predrag (2004-11-01)
    Mobile devices are severely power and area limited due to battery capacity and system size. In many of these example systems, advanced features require computationally complex signal processing on high-speed data streams ...
  • Chip level LMMSE Equalization for Downlink MIMO CDMA in fast fading environments 

    de Baynast, Alexandre; Radosavljevic, Predrag; Cavallaro, Joseph R. (2004-11-01)
    In this paper, we consider linear MMSE equalization for wireless downlink transmission with multiple transmit and receive antennas in fast fading environment. We propose a new algorithm based on conjugate-gradient algorithm ...
  • ASIP Architecture Implementation of Channel Equalization Algorithms for MIMO Systems in WCDMA Downlink 

    Radosavljevic, Predrag; Cavallaro, Joseph R.; de Baynast, Alexandre (2004-09-01)
    This paper presents a customized and flexible hardware implementation of linear iterative channel equalization algorithms for WCDMA downlink transmission in 3G wireless system with multiple transmit and receive antennas ...
  • Implementation of Iterative Channel Equalization for MIMO Systems in WCDMA Downlink 

    Radosavljevic, Predrag; Cavallaro, Joseph R.; de Baynast, Alexandre (2003-10-20)
    In downlink transmission, channel multipaths destroy the orthogonality between users causing Multiple Access Interference (MAI). In order to restore the orthogonality between the users, chip-level channel equalization based ...
  • Bayesian Blind PARAFAC Recievers forDS-CDMA Systems 

    de Baynast, Alexandre; Declercq, David; De Lathauwer, Lieven; Aazhang, Behnaam (2003-10-01)
    In this paper an original Bayesian approach for blind detec-tion for Code Division Multiple Access (CDMA) Systems in presence of spatial diversity at the receiver is developed. In the noiseless context, the blind ...
  • Blind PARAFAC Receivers for Multiple Access-Multiple Antenna Systems 

    de Baynast, Alexandre; De Lathauwer, Lieven; Aazhang, Behnaam (2003-10-01)
    In this paper, we present a new blind receiver for multiple access channel with multiple transmit antennas per user and multiple receive antennas (MIMO channel). After being multiplied by a spreading sequence, each user s ...