NASA Technical Reports Server (Ntrs) 19960009518: the Telecommunications and Data Acquisition Progress Report 42-123 by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19960009518: the Telecommunications and Data Acquisition Progress Report 42-123 by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19960051319: an Iterative Soft-Decision Decoding Algorithm by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19960051319: an Iterative Soft-Decision Decoding Algorithm by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19960051318: Soft-Decision Decoding Techniques for Linear Block Codes and Their Error Performance Analysis by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (N...
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NASA Technical Reports Server (Ntrs) 19960051318: Soft-Decision Decoding Techniques for Linear Block Codes and Their Error Performance Analysis by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19910022974: Multi-Dimensional Modulation Codes for Fading Channel by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19910022974: Multi-Dimensional Modulation Codes for Fading Channel by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19940017226: Design of a New Squaring Function for the Viterbi Algorithm by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19940017226: Design of a New Squaring Function for the Viterbi Algorithm by NASA Technical Reports Server (Ntrs); NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19930005581: High-Speed Architecture for the Decoding of trellis-Coded Modulation by NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19930005581: High-Speed Architecture for the Decoding of trellis-Coded Modulation by NASA Technical Reports Server (Ntrs); published by
We present a method for joint decode-and-forward physical layer network coding in two-way relay networks. The two source nodes send their packets simultaneously over time-varying channels to a relay node, then the rel...
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We present a method for joint decode-and-forward physical layer network coding in two-way relay networks. The two source nodes send their packets simultaneously over time-varying channels to a relay node, then the relay broadcasts the received superimposed packets to the source nodes using network coding. The nodes use trellis coding for the sake of error correction and multi-antenna equipments to combat multipath fading. A challenging multiple access problem occurs at the relay node, which performs joint channel estimation and decoding for the individual source packets. We design message passing algorithms based on factor-graphs to solve this problem. The relay has two separate modules that perform channel estimation and decoding for the packets received from each source node. The interference generated by the other source node is taken into account by exchanging messages between the two modules.
Spatial modulation (SM), in which multiple antennas are used to convey information besides the conventional M-ary signal constellations, is a new multiple-input multiple-output (MIMO) transmission technique, which has...
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Spatial modulation (SM), in which multiple antennas are used to convey information besides the conventional M-ary signal constellations, is a new multiple-input multiple-output (MIMO) transmission technique, which has recently been proposed as an alternative to V-BLAST (vertical Bell Labs layered space-time). In this paper, a novel MIMO transmission scheme, called spatial modulation with trellis coding (SM-TC), is proposed. Similar to the conventional trellis coded modulation (TCM), in this scheme, a trellis encoder and an SM mapper are jointly designed to take advantage of the benefits of both. A soft decision Viterbi decoder, which is fed with the soft information supplied by the optimal SM decoder, is used at the receiver. A pairwise error probability (PEP) upper bound is derived for the SM-TC scheme in uncorrelated quasi-static Rayleigh fading channels. From the PEP upper bound, code design criteria are given and then used to obtain new 4-, 8- and 16-state SM-TC schemes using quadrature phase-shift keying (QPSK) and 8-ary phase-shift keying (8-PSK) modulations for 2, 3 and 4 bits/s/Hz spectral efficiencies. It is shown via computer simulations and also supported by a theoretical error performance analysis that the proposed SM-TC schemes achieve significantly better error performance than the classical space-time trellis codes and coded V-BLAST systems at the same spectral efficiency, yet with reduced decoding complexity.
We study the maximum a posteriori (MAP) decoding of memoryless non-uniform sources over multiple-antenna channels. Our model is general enough to include space-time coding, BLAST architectures, and single-transmit mul...
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We study the maximum a posteriori (MAP) decoding of memoryless non-uniform sources over multiple-antenna channels. Our model is general enough to include space-time coding, BLAST architectures, and single-transmit multi-receive antenna systems which employ any type of channel coding. We derive a closed-form expression for the codeword pairwise error probability (PEP) of general multi-antenna codes using moment generating function and Laplace transform arguments. We then consider space-time orthogonal block (STOB) coding and prove that, similar to the maximum likelihood (ML) decoding case, detection of symbols is decoupled in MAP decoding. We also derive the symbol PEP in closed-form for STOB codes. We apply these results in several scenarios. First, we design a binary antipodal signaling scheme which minimizes the system bit error rate (BER) under STOB coding. At a BER of 10(-6), this constellation has a channel signal-to-noise ratio (CSNR) gain of 4.7 dB over conventional BPSK signaling for a binary non-uniform source with p(0) (sic) P(0) = 0.9. We next design space-time linear dispersion (LD) codes which are optimized for the source distribution under the criterion of minimizing the union upper bound on the frame error rate (FER). Two codes are given here: one outperforms V-BLAST by 3.5 dB and Alamouti's code by 12.3 dB at an FER of 10(-2) for a binary source with p(0) = 0.9, and the other outperforms V-BLAST by 4.2 dB at an FER of 10(-3) for a uniform source. These codes also outperform the LD codes of [13] constructed under a different criteria. Finally, the problem of bit-to-signal mapping is studied. It is shown that for a binary source with p(0) = 0.9, 64-QAM signaling, and SER = 10(-3), a gain of 3.7 dB can be achieved using a better-than-Gray mapping. For a system with one transmit and two receive antennas that uses trellis coding with 16-QAM signaling, a 1.8 dB gain over quasi-Gray mapping and ML decoding is observed when MAP decoding is used for binary so
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