Abstract:
A system to communicate optical data signals in parallel includes an optical splitter to split the data signals into two polarization multiplexed (PM) signals; and two reception channels coupled to the optical splitter, where each reception channel tracks and isolates a PM signal independently.
Abstract:
A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.
Abstract:
An optical communication system includes a bit-interleaved coded modulation (BICM) coder; and a low-density parity-check (LDPC) coder coupled to the BICM coder to generate codes used as component codes and in combination with a coherent detector.
Abstract:
A computer implemented testing framework for symbolic trace analysis of observed concurrent traces that uses MAT-based reduction to obtain succinct encoding of concurrency constraints, resulting in quadratic formulation in terms of number of transitions. We also present encoding of various violation conditions. Especially, for data races and deadlocks, we present techniques to infer and encode the respective conditions. Our experimental results show the efficacy of such encoding compared to previous encoding using cubic formulation. We provided proof of correctness of our symbolic encoding.
Abstract:
A system and method for dynamic data race detection for concurrent systems includes computing lockset information using a processor for different components of a concurrent system. A controlled execution of the system is performed where the controlled execution explores different interleavings of the concurrent components. The lockset information is used during the controlled execution to check whether a search subspace associated with a state in the execution is free of data races. A race-free search subspace is dynamically pruned to reduce resource usage.
Abstract:
Methods and systems for scheduling multicast transmissions that includes scheduling layered data for one or more multicast transmissions across a plurality of sub-channels using multi-resolution modulation. The sub-channels for each transmission may have diverse or uniform capacities. Scheduling includes allocating sub-channels to the layers of the layered data.
Abstract:
A model is provided for transforming a program with a priori given class hierarchy that is induced by inheritance. An inheritance remover is configured to remove inheritance from a given program to produce an analysis-friendly program which does not include virtual-function pointer tables and runtime libraries associated with inheritance-related operations. The analysis-friendly program preserves the semantics of the given program with respect to a given class hierarchy. A clarifier is configured to identify implicit expressions and function calls and transform the given program into at least one intermediate program having explicit expressions and function calls.
Abstract:
A system and method are disclosed which compensate for chromatic dispersion and polarization mode dispersion in a digital signal. The signal is adjusted for chromatic dispersion in the frequency-domain. The signal is then converted to the time-domain and at least a portion of the signal is estimated to produce channel parameters. The channel parameters are converted to the frequency domain and used to compensate for polarization mode dispersion in the signal.
Abstract:
An admission control system for a cloud database includes a machine learning prediction module to estimate a predicted probability for a newly arrived query with a deadline, if admitted into the cloud database, to finish its execution before said deadline, wherein the prediction considers query characteristics and current system conditions. The system also includes a decision module applying the predicted probability to admit a query into the cloud database with a target of profit maximization with an expected profit determined using one or more service level agreements (SLAs).
Abstract:
Methods and systems that enable the determination of accurate channel estimates by measuring only power values of pilot signal transmissions at a receiver are described. Various measurement procedures that are based on average power measurements or short term, per-symbol measurements can be employed. Furthermore, procedures utilizing adaptive pilots generated with receiver feedback and deterministic pilots generated without receiver feedback are also described.