Abstract: A method for determining symbols PSK modulated on an optical carrier includes interfering a first polarization component of the modulated optical carrier and a reference optical carrier in a first optical mixer and interfering the first polarization component of the modulated optical carrier and the reference with a different relative phase in a second optical mixer. The method also includes sampling the interfered carriers from the first optical mixer to produce first digital sampled values and sampling the interfered carriers from the second optical mixer to produce second digital sampled values. The first and second digital sampled values of a sampling period form a first complex sampling value thereof. The method also includes offsetting a phase of a complex signal value corresponding to each first complex sampling value to correct for a phase error caused by a frequency offset between the modulated and reference optical carriers.

Abstract: An apparatus, a polarization diversity receiver and a method of receiving a received optical signal. In one embodiment, the apparatus includes: (1) an optical device configured to separate in-phase and quadrature components of a received optical signal, to transmit the in-phase components to a first optical output thereof and to transmit the quadrature components to a second optical output thereof, (2) a first polarization splitter coupled to receive light at the first optical output and (3) a second polarization splitter coupled to receive light at the second optical output.

Abstract: A method and apparatus are provided for performing electronic equalization in optical communication systems. Coefficient values in equalizers, such as feed forward equalizers or decision feedback equalizers, are updated using higher-order algorithms in the Least-Mean-2Nth-Order family. An optical receiver includes a photo-detector for converting a received optical signal to an electrical signal; and an equalizer for removing intersymbol interference from the electrical signal, wherein coefficients of the equalizer are updated based upon a least-mean 2Nth-order (LMN) algorithm (N is greater than one). Feed forward equalizer and decision feedback equalizer implementations are disclosed. The non-symmetric nature of optical noise is addressed by varying A slicer threshold based on an incoming signal distribution to reduce bit errors.

Abstract: The electronic settlement system of the present invention is an electronic settlement system for the purpose of paying a plurality of expenses requested by the user within a predetermined time period using electronic settlement. It consists of a cash-deposit processing means, which processes cash deposits for each of the expense categories, a payment processing means that makes payments for each of the expense categories, as well as a memory which can store the payment method, payment period, scheduled payment amount and available credit information for each of the expense categories, spreadsheet management of payments and deposits made by the user in each of the categories using electronic settlement and a spreadsheet management means that sends notices to the user on a regular basis. Preferably, the above-mentioned memory will include an available credit correction means that can correct the content of the available credit contained in memory.

Abstract: A method and an apparatus of measuring a state of an IC lead frame are disclosed. The method has the steps of detecting a first projective position of an upper edge of a lead terminal of the IC lead frame on a reference surface and a second projective position of the upper edge, the second projective position of the upper edge having a projective angle different from that of the first projective position of the upper edge, detecting a first projective position of a lower edge of the lead terminal on the reference surface and a second projective position of the lower edge, the second projective position of the lower edge having a projective angle different from that of the first projective position of the lower edge, and computing the state of the lead terminal from the detections of the projective positions.