Practical Low density Lattice Codes

Speaker: Prof. Meir Feder , Tel-Aviv University and AMIMON.


Low density lattice codes (LDLC) are recently proposed lattice codes that can be decoded by linear-time iterative decoding and approach the capacity of the additive white Gaussian noise (AWGN) channel. In LDLC a codeword x is generated directly at the n-dimensional Euclidean space as a linear transformation of a corresponding integer message vector b, i.e., x = Gb, where H = G−1 is restricted to be sparse. In LDLC the messages are pdf's of the component of the real codeword x. In order to make LDLC practical for application we proposed parametric representation of the pdf's, making the decoding algorithm very efficient in storage and computations. Furthermore, for practical application, the infinite lattice should be combined with a shaping algorithm, that maps information bits to lattice points and ensures that the power of the lattice codewords is properly constrained. This work also proposes several efficient and practical shaping algorithms for LDLC. One technique establishes the notion of “systematic lattice codes”. As a result, LDLC are not only interesting theoretically, but can practically outperform any other proposed scheme for spectrally efficient communication. [Joint work with Naftali Sommer, Ofir Shalvi and Yair Yona]

Bio: Meir Feder received the B.Sc. and M.Sc. degrees (Summa Cum Laude) in Electrical Engineering from Tel-Aviv University, in 1980 and 1984, respectively and the Sc.D. degree from MIT in 1987. In 1990 he joined the Department of Electrical Engineering - Systems, Tel-Aviv University, where he is now a Professor. He also had visiting positions at MIT, Woods Hole Oceanographic Institution, Bell Laboratories and UCSD. His research include topics in signal processing, communication, data compression and information theory in general. He got several awards, including the 1993 best paper award of the Information Theory for his work on universal prediction.

In parallel to his academic career, Meir Feder is highly involved in the high-tech industry. In 1998 he co-founded Peach Networks, a provider of server-based interactive TV systems, which acquired by Microsoft. In 2000 he co-founded Bandwiz, a provider of massive content delivery systems for enterprise networks. He is now involved with Amimon, which he co-founded in 2004. Amimon, the developer of “Wireless Home Digital Interface” (WHDI™) technology is an emerging leading provider of ASICs for wireless high-definition A/V connectivity at the home. He also serves on the board and advisory board of several start-up companies.