Abstract: A system and method for dynamically modifying scheduling of scan operations for a system under test includes a processing module configured to apply input test data to the system under test based on the scan operations via a test access port and a scheduler adapted to provide the processing module with scheduling for the plurality of scan operations. The scheduler includes a circuit model of the system under test. The circuit model includes at least one attribute providing enhancing information for at least a portion of the system under test. The scheduler is adapted to schedule the scan operations based on the circuit model and to modify the schedule based on the at least one attribute. The processing module is configured to receive the modified scheduled scan operations and to apply the input test data to the system under test based on the modified scheduled scan operations.

Abstract: Methods and apparatus for power-efficiently and reliably transmitting high-level quadrature amplitude modulation (QAM) optical signals using binary drive signals. Even though binary signals are used to drive a QAM modulator directly, without digital-to-analog conversion, the methods and apparatus disclosed allow the transmission of pilot symbol sequences having near optimal properties, such as a constant power profile in the time domain; a mean power that is approximately the same as the mean power of the data symbols; and roughly uniform amplitude in the frequency domain for non-zero frequency components of the pilot symbol sequence. The binary drive signals can be processed so that the modulated optical signals are selectively constrained to a subset of points of the QAM constellation to form a QAM constellation with reduced size and a mean power that is approximately the same as the mean power of the original QAM constellation.

Abstract: An all-optical modulation format converter for converting optical data signals modulated in an on-off-keying (OOK) format to a phase-shift-keying (PSK) format. The OOK-to-PSK converter can be coupled to a delay-line interferometer to provide an all-optical wavelength converter for differential PSK (DPSK). The OOK-to-PSK converter can also be used in all-optical implementations of various functions, including, for example, exclusive-OR (XOR/NXOR) and OR logic, shift registers, and pseudo-random binary sequence (PRBS) generators. Several variants of all-optical devices are described.

Abstract: Power allocation methods for multiuser orthogonal frequency division multiplexing (OFDM) are described. Arbitrary partitioning of the OFDM tones among users and arbitrary modulation formats, possibly different for every user, are considered. Two systems of receivers and transmitters and corresponding methods address power allocation, respectively for slow fading channels tracked instantaneously by the system and for fast fading channels known only statistically thereby.