Settings

Now showing1 - 10 of 77
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Error Bound Analysis of Chip-to-Chip Communication Based on Spectrum Shaping
    (2019-11)
    Zhao, Yu
    ;
    Grünheid, Rainer
    ;
    Bauch, Gerhard
    Spectrum shaping is a good candidate for improving the efficiency of chip-to-chip communication systems. In recent years, distinct spectrum shaping schemes have been proposed for different chip-to-chip communication channels. However, a general metric on the suitability of spectrum shaping schemes is still lacking. This work addresses the problem through theoretical analysis. Two methods are utilized in the investigation, capacity achievement and error probability minimization. For the first time to our knowledge, the relation between bit error probability (BEP) and spectrum shaping is analyzed for chip-to-chip communication systems. The results facilitate the error bounds calculation of different spectrum shaping schemes, which provides a good reference for the design on the strategy of spectrum shaping.
    Publicationtype: Conference Paper
      91
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: with files ,
    Coarsely quantized decoding and construction of polar codes using the information bottleneck method
    (Multidisciplinary Digital Publishing Institute (MDPI), 2019-09-10)
    Shah, Aizaz
    ;
    Stark, Maximilian
    ;
    Bauch, Gerhard
    The information bottleneck method is a generic clustering framework from the field of machine learning which allows compressing an observed quantity while retaining as much of the mutual information it shares with the quantity of primary relevance as possible. The framework was recently used to design message-passing decoders for low-density parity-check codes in which all the arithmetic operations on log-likelihood ratios are replaced by table lookups of unsigned integers. This paper presents, in detail, the application of the information bottleneck method to polar codes, where the framework is used to compress the virtual bit channels defined in the code structure and show that the benefits are twofold. On the one hand, the compression restricts the output alphabet of the bit channels to a manageable size. This facilitates computing the capacities of the bit channels in order to identify the ones with larger capacities. On the other hand, the intermediate steps of the compression process can be used to replace the log-likelihood ratio computations in the decoder with table lookups of unsigned integers. Hence, a single procedure produces a polar encoder as well as its tailored, quantized decoder. Moreover, we also use a technique called message alignment to reduce the space complexity of the quantized decoder obtained using the information bottleneck framework.
    Publicationtype: Journal Article
    Scopus© Citations 12  400  323
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Enabling Situational Awareness in Millimeter Wave Massive MIMO Systems
    (2019-09)
    Mendrzik, Rico
    ;
    Meyer, Florian
    ;
    Bauch, Gerhard
    ;
    Win, Moe Z.
    Situational awareness in wireless networks refers to the availability of position information on transmitters and receivers as well as information on their propagation environments to aid wireless communications. In millimeter wave massive multiple-input multiple-output communication systems, situational awareness can significantly improve the quality and robustness of communications. In this paper, we establish a model that describes the statistical dependencies between channel state information and the position, orientation, and clock offset of a user equipment along with the locations of features in the propagation environment. Based on this model, we introduce COMPAS (COncurrent Mapping, Positioning, And Synchronization); an inference engine that can provide accurate and reliable situational awareness in millimeter wave massive multiple-input multiple-output communication systems. Numerical results show that COMPAS is able to infer the positions of an unknown and time-varying number of features in the propagation environment and, at the same time, estimate the position, orientation, and clock offset of a user equipment.
    Publicationtype: Journal Article
      344
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      316
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      174
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: with files ,
    A low complexity spectrum shaping scheme for substrate integrated waveguides based on spread reshaping code
    (2019-08-24)
    Zhao, Yu
    ;
    Grünheid, Rainer
    ;
    Bauch, Gerhard
    In the microwave and millimeter-wave transmission regions, substrate-integrated waveguide (SIW) is a very promising candidate for the development of circuits and components. The channel of the SIW is a bandpass or high pass filter. This characteristic impedes the conventional baseband transmission using nonreturn-to-zero pulse shaping scheme. As an alternative to using mixers to facilitate a passband transmission, this paper proposes a spectrum shaping scheme of low complexity for the channel of SIW, namely spread reshaping code. It aims at matching the spectrum of the transmit signal to the channel frequency response. It facilitates the transmission through the SIW channel while it avoids using carrier modulation and equalization. Simulations reveal a good performance of this scheme, such that, as a result, eye opening is achieved without any equalization or modulation for the respective transmission channels.
    Publicationtype: Journal Article
      426  282
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      115
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      297
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    An Energy Efficient Spectrum Shaping Scheme for Substrate Integrated Waveguides
    (2019-06)
    Zhao, Yu
    ;
    Grünheid, Rainer
    ;
    Bauch, Gerhard
    In the microwave and millimeter-wave transmission region, substrate-integrated waveguide (SIW) is a very promising candidate for the development of circuits and components. An SIW mimics a rectangular waveguide by approximating the closed sidewalls with a via fence. This structure suppresses the low frequency components and makes the channel of the SIW a bandpass or high pass filter. This channel characteristic impedes the conventional baseband transmission using non-return-to-zero (NRZ) pulse shaping scheme. Therefore, mixers are commonly proposed to be used as carrier modulator and demodulator in order to facilitate a passband transmission. However, carrier modulation is not an energy efficient solution, because modulation and demodulation at high frequencies consume a lot of energy. For the first time to our knowledge, this paper proposes a spectrum shaping scheme of low complexity for the channel of SIW, namely spread reshaping code. It aims at matching the spectrum of the transmit signal to the channel frequency response. It facilitates the transmission through the SIW channel while it avoids using carrier modulation. Simulations reveal a good performance of this scheme, such that, as a result, eye opening is achieved without any receiver equalization or modulation for the respective transmission channels.
    Publicationtype: Conference Paper
      157
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Decoding of Non-Binary LDPC Codes using the Information Bottleneck Method
    (2019-05)
    Stark, Maximilian
    ;
    Bauch, Gerhard
    ;
    Lewandowsky, Jan
    ;
    Saha, Souradip
    Recently, a novel lookup table based decoding method for binary low-density parity-check codes has attracted considerable attention. In this approach, mutual-information-maximizing lookup tables replace the conventional operations of the variable nodes and the check nodes in message passing decoding. Moreover, the exchanged messages are represented by integers with very small bit width. A machine learning framework termed the information bottleneck method is used to design the corresponding lookup tables. In this paper, we extend this decoding principle from binary to non-binary codes. This is not a straightforward extension but requires a more sophisticated lookup table design to cope with the arithmetic in higher order Galois fields. Provided bit error rate simulations show that our proposed scheme outperforms the log-max decoding algorithm and operates close to sum-product decoding.
    Publicationtype: Conference Paper
      186