Abstract: A system and method for pointer analysis for computer program verification includes forming a subset or cluster of pointers from pointers in a program by applying increasingly accurate alias analyses in a cascaded fashion such that each analysis works on a subset of pointers generated by a previous analysis's results. Aliases are computed for any pointer by computing aliases in the subsets in parallel instead of an entire program. For carrying out context and flow-sensitive alias analysis, function summaries are computed on small subsets in a top-down manner based on the points-to hierarchy which reduces the sizes of the summaries.

Abstract: Systems and methods for joint training of beam patterns in a system having a transmitter and a receiver. Initial transmit and receive beam pattern vectors are first selected. The beam pattern vectors are perturbed to produce a plurality of perturbed transmit and receive beam pattern vectors. A received signal power between the transmitter and the receiver is estimated for each combination of the perturbed transmit and the perturbed receive beam pattern vectors. The transmit and receive beam pattern vectors having a highest received signal power are applied to the transmitter and the receiver respectively. The perturbation, estimation, and application steps are iterated until the received signal power meets a convergence criterion.

Abstract: A decoder and method for iteratively decoding of low-density parity check codes (LDPC) includes, in a code graph, performing check node decoding by determining messages from check nodes to variable nodes. In the code graph, variable node decoding is performed by determining messages from the variable nodes to the check nodes. The variable node decoding is independent from degree information regarding the variable nodes. Decoded results are output.

Abstract: A scheduling system and method for use with relay-assisted wireless networks includes accessing feedback from mobile stations in a network and arranging users associated with a relay station in a list in accordance with marginal utilities. A determination of whether the users in the list can be eliminated from feedback overhead by testing conditions for feedback reduction is made. A diversity schedule is generated by employing a weighted bipartite graph with relay channels and access channels and performing a matching method. A transmission schedule is generated for channel usage in accordance with multi-user and channel diversity for mobile users and spatial reuse of channels across relay and access hops by incorporating rate feedback and interference for the mobile stations and the relay stations based upon the matching method applied to a new weighted graph which accounts for traffic loads and fairness as well.

Abstract: Methods and systems for controlling power fluctuations in a network including a plurality of nodes are disclosed. A node in the network may be configured to modify power levels in accordance with either an active state or an inactive state. The node may transition to an inactive state in response to a power change that exceeds a power change threshold. The role of the node in controlling the power fluctuation in the network is reduced in the inactive state.

Abstract: An optical system and method includes a source-free optical network unit coupled to an optical fiber for receiving a centralized lightwave carrier signal with downstream data over the optical fiber. The optical network unit includes a coupler configured to split the original carrier signal into a first path and a second path. The first path includes an optical filter configured to reduce fading effects of the carrier signal. The second path includes a modulator configured to remodulate the centralized lightwave carrier signal with upstream data to produce an upstream data signal for upstream transmission.

Abstract: A system and method for inferring preconditions for procedures in a program includes formulating predicates based on inputs to a procedure, including formal arguments, global variables and external environment. Truth assignments are sampled to the predicates to provide truth assignments that lead to a feasible set of input values. Test cases are generated for testing the program in accordance with the truth assignments having feasible sets of input values. The truth assignments are classified to the predicates as providing an error or not providing an error.

Abstract: A network system and method include a wireless base station integrated at a central office of a service provider. The wireless base station is configured to provide portable and fixed services to customers. A passive optical network is coupled to the wireless base station at the central office to provide a link to extend an antenna for wireless operations of the wireless base station to a remote site such that a wireless signal from the wireless base station is transmitted in parallel with a passive fiber network signal through the link.

Abstract: A method for error correction and a decoder using low density parity check (LDPC) codes includes initializing extrinsic probability information between variable nodes and check nodes in a bipartite graph including generating a Bernoulli sequence according to a probability of a bit having a value one. Parity checking is performed in accordance with a parity check equation. If the parity check equation is not satisfied, then extrinsic information is updated in check nodes from variable nodes using a parity node update logic circuit in a first half iteration, extrinsic information is updated in variable nodes from check nodes using a variable node update logic circuit in a second half iteration, and the variable nodes are updated with a probability based upon the extrinsic information passed between check nodes and variable nodes wherein the probability represents a likelihood that an ith bit is a one.

Abstract: A differential delay detection system and method includes an optical splitter to split an incoming optical signal between a first path and a second path. The first path includes a cross-polarization interferometer configured to separately generate polarization independent outputs using split paths and to generate cross-polarization interference outputs, balanced photodetectors to aid in removing cross-polarization beating noise, and a polarization demultiplexer configured to combine the polarization independent outputs and the cross-polarization interference outputs from the cross-polarization interferometer with updated coefficients received from the second path to remove the cross-polarization mixed signals. The second path includes a training signal receiver configured to compute the updated coefficients and output the updated coefficients to the polarization demultiplexer.

Abstract: A system and method for optimizing system performance includes applying sampling based optimization to identify optimal configurations of a computing system by selecting a number of configuration samples and evaluating system performance based on the samples. Based on feedback of evaluated samples, a location of an optimal configuration is inferred. Additional samples are generated towards the location of the inferred optimal configuration to further optimize a system configuration.

Abstract: A differential delay detection system and method includes an optical splitter to split an incoming optical signal between a first path and a second path. The first path includes a cross-polarization interferometer configured to separately generate polarization independent outputs using split paths and to generate cross-polarization interference outputs, and a polarization demultiplexer configured to combine the polarization independent outputs and the cross-polarization interference outputs from the cross-polarization interferometer with updated coefficients received from the second path to remove the cross-polarization mixed signals. The second path includes a training signal receiver configured to compute the updated coefficients and output the updated coefficients to the polarization demultiplexer.

Abstract: A system and method for characterizing noise in a quantum system includes determining pulse sequences for unitary twirling operations. Twirling processes are applied to a quantum system to calibrate errors and to determine channel parameters. Noise characteristics are determined from calibration data collected to calibrate the errors and to determine the channel parameters. The noise characteristics are characterized to determine if the noise is independent relaxation of qubits or collective relaxation of qubits.

Abstract: A demodulator and demodulation method includes a bit/symbol hard demodulator configured to obtain hard bit or symbol information from a received signal. At least one lookup table is configured to reference coefficients for computation of log-likelihood ratios (LLRs) from the hard bit or symbol information. A log-likelihood ratio calculation module is configured to compute bit-level LLRs from the coefficients and the received signal.

Abstract: A turbo equalizer includes a Bahl-Cocke-Jelinek-Raviv (BCJR) equalizer configured to receive a transmitted signal and partially cancel inter-symbol interference (ISI) due to polarization-mode dispersion (PMD). A low-density parity check (LDPC) decoder is coupled to the BCJR equalizer to receive channel bit reliabilities therefrom. The LDPC decoder iteratively provides extrinsic soft information feedback to the BCJR equalizer to compensate for PMD.

Abstract: A passive optical network (PON) device, system and method include an optical line terminal (OLT) receiver configured to receive multiple signals at different wavelengths simultaneously and enable multiple transmitters to operate at the same time during one upstream time slot. The optical line terminal employs Orthogonal Frequency Division Multiple Access (OFDMA) to transparently support a plurality of applications and enable dynamic bandwidth allocation among these applications where the bandwidth is allocated in two dimensional frequency and time space.

Abstract: Exemplary systems and methods in accordance with embodiments of the present invention may provide a plurality of data services by employing splittable, mergable and transferable redundant chains of data containers. The chains and containers may be automatically split and/or merged in response to changes in storage node network configurations and may be stored in erasure coded fragments distributed across different storage nodes. Data services provided in a distributed secondary storage system utilizing redundant chains of containers may include global deduplication, dynamic scalability, support for multiple redundancy classes, data location, fast reading and writing of data and rebuilding of data due to node or disk failures.

Abstract: A transmitter includes a plurality of encoders configured to receive source bit streams from m information sources, each of the plurality encoders including identical (n,k) low-density parity check (LDPC) codes of code rate r=k/n, where k is a number of information bits and n is codeword length. An interleaver is configured to collect m row-wise codewords from the plurality of encoders, and a mapper is configured to receive m bits at a time column-wise from the interleaver and to determine an M-ary signal constellation point. A modulator is configured to modulate a light source in accordance with the output of the mapper at a transmission rate Rs/r (Rs—the symbol rate, r—-the code rate). A receiver and transmission and receiving methods are also disclosed.

Abstract: A transmitter and method include a LDPC encoder configured to encode source data, and a mapper configured to generate three coordinates in accordance with a 3D signal constellation where the coordinates include an amplitude coordinate and two phase coordinates. A laser source is modulated in accordance with each of the three coordinates to provide a transmission signal. A receiver, includes a demapper receives an input signal from three branches to demap the input signal using a three-dimensional signal constellation having three coordinates. The three branches include a direct detection branch, and two coherent detection branches such that the direct detection branch detects an amplitude coordinate of the input signal and the two coherent detection branches detect in-phase and quadrature coordinates of the input signal. A bit prediction module and at least one LDPC decoder are configured to iteratively decode bits by feeding back extrinsic LLRs to the demapper.

Abstract: A system and method for support vector machine plus (SVM+) computations include selecting a set of indexes for a target function to create a quadratic function depending on a number of variables, and reducing the number of variables to two in the quadratic function using linear constraints. An extreme point is computed for the quadratic function in closed form. A two-dimensional set is defined where the indexes determine whether a data point is in the two-dimensional set or not. A determination is made of whether the extreme point belongs to the two-dimensional set. If the extreme point belongs to the two-dimensional set, the extreme point defines a maximum and defines a new set of parameters for a next iteration. Otherwise, the quadratic function is restricted on at least one boundary of the two-dimensional set to create a one-dimensional quadratic function. The steps are repeated until the maximum is determined.