B. Pitakdumrongkija

Tokyo Institute of Technology, Tokyo, Tokyo-to, Japan

Are you B. Pitakdumrongkija?

Claim your profile

Publications (7)2.06 Total impact

  • Boonsarn Pitakdumrongkija, Kazuhiko Fukawa, Satoshi Suyama, Hiroshi Suzuki, Atsuo Umi
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a MIMO-OFDM precoder that can minimize a BER upper bound of the maximum likelihood detector (MLD) under a non-cooperative downlink multicell co-channel interference (CCI) environment. Since there is no cooperation among base stations (BSs), it is assumed that information on the interference can be estimated at a mobile station (MS) and then fed back to the desired BS for the precoder. The proposed scheme controls its precoding parameters under a transmit power constraint so as to minimize the BER upper bound, which is derived from the pairwise error probability (PEP) averaged with respect to CCI plus noise. Computer simulations demonstrate that the proposed precoder can effectively improve BER performance of cell edge users and is superior in terms of BER to the eigenmode and the minimum mean squared error (MMSE) precoded transmissions which aim to maximize the channel capacity and to minimize MSE, respectively.
    IEICE Transactions. 01/2009; 92-B:1573-1581.
  • Source
    B. Pitakdumrongkija, K. Fukawa, H. Suzuki
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a minimum BER (MBER) based precoder that is robust to imperfect channel state information (CSI) for MIMO-OFDM mobile communications. The proposed MBER precoding aims to minimize BER of the maximum likelihood detection (MLD), on the condition that the transmitter can obtain only imperfect CSI owing to channel estimation and quantization errors of the feedback CSI. The proposed scheme controls its precoding parameters under a transmit power constraint by minimizing an upper bound of BER which is derived from the pairwise error probability and then averaged with respect to the CSI error. Computer simulations demonstrate that the proposed precoding method outperforms a conventional nonrobust MBER precoder and a conventional robust power allocation MBER precoder.
    Communications, 2008. ICC '08. IEEE International Conference on; 06/2008
  • B. Pitakdumrongkija, H. Suzuki, S. Suyama, K. Fukawa
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a novel single-sideband quadrature phase shift keying (SSB QPSK) modulation scheme that utilizes a single-reference carrier frequency and transforms both baseband I and Q components into the same radio frequency band, whose width is exactly half that of QPSK. The modulation method is first derived and followed by the analysis of the matched filter demodulation. The analysis shows that there are performance degradations due to intersymbol interference (ISI) in the received signal and correlation in the received noise. To suppress the degradations, this paper employs a turbo equalizer for demodulation, in which the effects of ISI and noise correlation can be suppressed by a soft canceler and a noise whitening filter in the minimum mean square error (MMSE) linear equalizer, respectively. The computer simulations are then used to verify the proposed modulation scheme. At the transmitter, the root-raised cosine rolloff filter is employed for pulse shaping and Hilbert-transformed pulse generation. The truncation of the signal pulse is performed by the window function. The results show that the proposed modulation scheme outperforms 16-quadratic-amplitude modulation (16-QAM) with the turbo code in the Rayleigh-fading environment.
    IEEE Transactions on Vehicular Technology 02/2008; · 2.06 Impact Factor
  • Source
    Boonsarn Pitakdumrongkija, Kazuhiko Fukawa, Hiroshi Suzuki, Takashi Hagiwara
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a new MIMO-OFDM precoding technique that aims to minimize a bit error rate (BER) upper bound of the maximum likelihood detection (MLD) in mobile radio communications. Using a steepest descent algorithm, the proposed method estimates linear precoding matrices that can minimize the upper bound of BER under power constraints. Since the upper bound is derived from all the pairwise error probabilities, this method can effectively optimize overall Euclidean distances between signals received by multiple antennas and their replicas. Computer simulations evaluate the BER performance and channel capacity of the proposed scheme for 2×2 and 4×4 MIMO-OFDM systems with BPSK, QPSK, and 16QAM. It is demonstrated that the proposed precoding technique is superior in terms of average BER to conventional precoding methods including a precoder which maximizes only the minimum Euclidean distance as the worst case.
    IEICE Transactions. 01/2008; 91-B:2287-2298.
  • Boonsarn Pitakdumrongkija, Kazuhiko Fukawa, Hiroshi Suzuki
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a new minimum BER (MBER) criterion precoding method that is robust to imperfect channel state information (CSI) for MIMO-OFDM mobile communications. The proposed MBER precoding aims to minimize BER of the maximum likelihood detection (MLD), on the condition that the transmitter can obtain only imperfect CSI owing to channel estimation and quantization errors of the feedback CSI. The proposed scheme controls its precoding parameters under a transmit power constraint by minimizing an upper bound of BER which is derived from the pairwise error probability and averaged with respect to the CSI error. In contrast with a conventional power allocation MBER precoding method that is also robust to the CSI error, the proposed scheme does not make any assumption on the precoding parameters so as to reduce complexity. Thus, it is expected to outperform the conventional scheme at the cost of higher complexity. Computer simulations demonstrate that the proposed precoding method outperforms a conventional nonrobust MBER precoder and the conventional robust power allocation MBER precoding method when the amount of the CSI error is not considerable.
    IEICE Transactions. 01/2008; 91-B:1490-1501.
  • Source
    B. Pitakdumrongkija, K. Fukawa, H. Suzuki, T. Hagiwara
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a new MIMO-OFDM preceding method that minimizes BER of the maximum likelihood detection (MLD). Conventional MIMO precoding methods can approximately minimize BER of the minimum mean square error (MMSE) based detector by using singular value decomposition (SVD) of the channel matrices. However, they cannot minimize BER of MLD because the orthogonalization does not increase the Euclidean distance between a pair of channel-distorted replicas of transmitted signals. To optimize the Euclidean distance effectively, the proposed method controls its precoding parameters by minimizing the upper bound of BER based on the pairwise error. Computer simulations demonstrate that the proposed precoding method outperforms the MMSE precoder and the conventional minimum BER (MBER) precoder that assumes the precoding matrix structure similar to the solution of the weighted MMSE precoder.
    Communications, 2007. ICC '07. IEEE International Conference on; 07/2007
  • B. Pitakdumrongkija, H. Suzuki, S. Suyama, K. Fukawa
    [Show abstract] [Hide abstract]
    ABSTRACT: The paper proposes a novel single sideband (SSB) QPSK modulation scheme that can guarantee half of the standard QPSK bandwidth by using only one carrier, in contrast with conventional schemes. Since the proposed scheme suffers from intersymbol interference (ISI), even in the additive white Gaussian noise (AWGN) channel, a soft-canceller (SC)/simplified-minimum mean square error (S-MMSE) type equalizer is employed. Computer simulation results show that the proposed single sideband QPSK can outperform 16QAM with the turbo code in a flat fading channel.
    Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st; 01/2005