Multilevel 2D bar codes: toward high-capacity storage modules for multimedia security and management

Multistage decoding of multilevel block multilevel phase-shift keying (M-PSK) modulation codes for the additive white Gaussian noise (AWGN) channel is investigated. Several types of multistage decoding, including a suboptimum soft-decision decoding scheme, are devised and analyzed. Upper bounds on the probability of an incorrect decoding of a code are derived for the proposed multistage decoding schemes. Error probabilities of some specific multilevel block 8-PSK modulation codes are evaluated and simulated. The computation and simulation results for these codes show that with multistage decoding, significant coding gains can be achieved with large reduction in decoding complexity. In one example, it is shown that the difference in performance between the proposed suboptimum multistage soft-decision decoding and the single-stage optimum decoding is small, only a fraction of a dB loss in SNR at the block error probability of 10/sup -6/. >

The achievable information rates for multilevel coding (MLC) systems with multistage decoding (MSD) are examined on two-dimensional binary-input intersymbol interference (ISI) channels. One MSD scheme employs trellis-based detection, while another involves zero-forcing equalization and linear noise prediction. Information rates are determined by examining the output statistics at each stage of MSD. The first scheme is shown to achieve rates very close to known information-theoretic limits. Systems with low-density parity-check codes are then optimized to approach these rates

Coding for the fading channel: a survey

A novel construction of lattices is proposed. This construction can be thought of as a special class of Construction A from codes over finite rings that can be represented as the Cartesian product of $L$ linear codes over $\mathbb {F}_{p_{1}},\ldots ,\mathbb {F}_{p_{L}}$ , respectively, and hence is referred to as Construction $\pi _{A}$ . The existence of a sequence of such lattices that is good for channel coding (i.e., Poltyrev-limit achieving) under multistage decoding is shown. A new family of multilevel nested lattice codes based on Construction $\pi _{A}$ lattices is proposed and its achievable rate for the additive white Gaussian noise channel is analyzed. A generalization named Construction $\pi _{D}$ is also investigated, which subsumes Construction A with codes over prime fields, Construction D, and Construction $\pi _{A}$ as special cases.

This paper presents a new study in an attempt to apply Fast Euclidean Direction Search (FEDS) algorithm on adaptive smart antennas. The novelty in this work is the use of FEDS algorithm in a smart antenna system for mobile communications because up to our knowledge this algorithm is not applied on smart antenna so far. In order to properly evaluate the performance of smart antenna for mobile communication systems, an Additive White Gaussian Noise (AWGN) channel model is required that each received signal at each element in the array includes only an additive, zero mean, Gaussian noise . The ability of the FEDS algorithm to operate in a fast changing signal environment is examined by subjecting the input signal to Rayleigh fading with a Jakes power spectral density which is a popular choice for land mobile communications systems. Through simulation results of smart antennas for AWGN channel, the RLS and FEDS start to converge from the initial iteration and 10 respectively, whereas, the LMS and NLMS start to converge after 50 and 10 iterations respectively. In the presence of the Rayleigh fading channel, the LMS, and NLMS algorithms converge after 60 and 25 iterations respectively, while the RLS convergence from the initial iteration and FEDS converge from the iteration number 25. On the other hands, the FEDS algorithm shows better tracking and estimation of the desired input signal compared with both LMS and NLMS algorithms and comparable with RLS algorithm. The comparison of linear plot of array factor using FEDS and RLS , both algorithms generates the same deeper null for undesired signals of about í30 dB towards the interferer using an AWGN channel, while it generates deeper null of about -23 dB and -30 dB respectively using the Rayleigh fading channel.

The concatenation scheme MLC-STBC combining multilevel codes (MLC) and space-time block codes (STBC) is proposed over Rayleigh fading channels. Through performance analysis and computer simulation, the asymptotic behavior of the new system is provided, which is proportional to the product of the space diversity and the minimum Hamming distance of the component codes. The simulation results show that, with the same bandwidth efficiency, the concatenation scheme has better power efficiency than the MLC system. Considering the fact that multistage decoding (MSD) and parallel decoding on levels (PDL) have a little difference in the system performance, the concatenation scheme MLC-STBC with PDL decoding method (MLC-STBC/PDL) achieves better trade-off between performance and complexity.

In modern wireless communication systems, wireless channel modeling has always been a fundamental task in system design and performance optimization. Traditional channel modeling methods, such as ray-tracing and geometry- based stochastic channel models, require in-depth domain-specific knowledge and technical expertise in radio signal propagations across electromagnetic fields. To avoid these difficulties and complexities, a novel generative adversarial network (GAN) framework is proposed for the first time to address the problem of autonomous wireless channel modeling without complex theoretical analysis or data processing. Specifically, the GAN is trained by raw measurement data to reach the Nash equilibrium of a MinMax game between a channel data generator and a channel data discriminator. Once this process converges, the resulting channel data generator is extracted as the target channel model for a specific application scenario. To demonstrate, the distribution of a typical additive white Gaussian noise channel is successfully approximated by using the proposed GAN-based channel modeling framework, thus verifying its good performance and effectiveness.

Semialgebraic low-density parity-check (SA-LDPC) codes are proposed for the multilevel coded modulation system. We optimize code parameters of LDPC codes according to the rate of each level by Gaussian approximation. Iterative multistage decoding (IMSD) scheme is adopted to get the significant improvement. System performance with Ungerboeck partitioning (UP) and mixed partitioning (MP) for 8PSK is evaluated respectively over additive white Gaussian noise (AWGN) channels. Many results are presented, they indicate that in terms of the tradeoff between hardware complexity and system performance, constructed multilevel coded modulation system based on optimized LDPC codes, capacity rule and MP is a good choice for the bandwidth efficient transmission over AWGN channels.

Our objective is to design efficient coded modulation techniques with multi-stage decoding (MSD) for Rayleigh fading channels. The well-known rate design rule is conventionally used for AWGN channels. We extend the application of the rate design rule for multi-level coding by considering MSD for Rayleigh fading channels with interleaving. We model the fading channel as a time invariant additive non-Gaussian noise channels by assuming that the perfect channel state information is available at the receiver. The equivalent channel capacity curves that can be used for the multi-level code design for Rayleigh channels, and a code design example are presented. We demonstrate that a very good coding gain can be achieved if code rates are selected correctly.

In this paper a coded modulation method for the additive white Gaussian noise channel is presented which incorporates signal shaping. The scheme uses a modulation map to map bits to channel inputs. A modulation map is considered that has the advantage it is can easily be combined with binary error-correcting codes. The decoding strategy is a combination of bit-interleaved coded modulation and multistage decoding. The number of required decoding stages is only small compared to other multistage decoding schemes for coded modulation. It is shown that modulation maps can be designed with a constrained capacity limit very close to the capacity of the AWGN channel. When combined with low-density parity-check codes, simulation results show that a near-capacity performance is achieved for high spectral efficiencies.

Coding Schemes for Energy Constrained IoT Devices

We first present a formulation for the real-time tracking of a scalar continuous-time linear process over an Additive White Gaussian Noise (AWGN) channel without channel feedback and prove several results for minimum mean-squared error (MMSE) tracking. For the one-to-one channel case, we give an optimal encoder-decoder pair along with the optimal tracking performance. With the Gaussian distributed source innovation, one optimal form of the encoder is shown to be a linear innovation encoder, which scales the source innovation to match with the power constraint of the channel input. We then extend the formulation to the case where multiple source processes are tracked via a shared AWGN channel.

This paper studies the optimal reference tracking problems of finite-dimensional, linear, time-invariant (LTI) systems with an additive white Gaussian noise (AWGN) channel between the controller and the plant. We consider two types of the reference signal: a random variable and a Brownian motion. The power of the tracking error is adopted as the measure of the performance and is to be minimized over all stabilizing two-parameter controllers. We assume the power of the channel input is limited and seek to solve the constrained optimization problem explicitly. It is shown that, besides the power constraint, the lowest power of the tracking error hinges closely on non-minimum phase zeros, the unstable poles and the plant gain.

We analyze the general form of the extrinsic information transfer curve of polar codes viewed as multilevel codes with multistage decoding. Based on this analysis, we propose a graphical design methodology to construct polar codes for intersymbol interference channels. The method matches the extrinsic information transfer curve of the code to that of the intersymbol interference channels, so that there is an open convergence tunnel between the two. We show that polar codes can provide such a matching to the channel curve under soft-cancellation decoding and propose one such method to achieve it. Example code designs are presented to demonstrate that polar codes that are optimized for an ISI channel can significantly outperform polar codes that are designed for an AWGN channel.

PDF417-based card carrying the much information is an international defacto standard for verification, registration, or other data management of the government issued card. In this paper, the PDF417 symbol (a two-dimensional (2D) bar code) is divided