Abstract: A direct digital radio having a high speed RF front end in communication with an antenna, and a radio subsystem that can be configured to form a multi-channel, full duplex transceiver system. The high speed RF front end provides a digital signal to the radio subsystem. Each transceiver includes a waveform processing subsystem that makes use of a linear, phase-B cubic spline interpolating finite impulse response (IFIR) filter for filtering the received RF signal substantially entirely in the digital domain. The linear phase-B, cubic spline IFIR filter requires significantly fewer hardware components than traditional FIR filters and is ideally suited for implementation using Very Large Scale Integration (VLSI) technology.

Abstract: A filter for high speed digital signal processing. In one embodiment the filter includes a linear, phase-B, interpolating cubic spline filter having a pre-filter section and an interpolating post-filter section. The pre-filter section may be formed to implement any one of a 1-4-1 cubic spline function, a 2-5-2 cubic spline function or a 1-2-1 cubic spline function. The post-filter may be formed using a plurality of running average filters arranged in a cascade (i.e., serial) fashion. The filter can be constructed using significantly fewer independent component parts for a given level of pass band and stop band performance criteria, as compared with a conventional finite impulse response (FIR) filter. The filter is thus ideally suited for implementation with very large scale integration (VLSI) technology, and in a wide variety of electronic devices where high speed digital filtering is required.

Abstract: A filter for high speed digital signal processing. In one embodiment the filter includes a linear, phase-B, interpolating cubic spline filter having a pre-filter section and an interpolating post-filter section. The pre-filter section may be formed to implement any one of a 1-4-1 cubic spline function, a 2-5-2 cubic spline function or a 1-2-1 cubic spline function. The post-filter may be formed using a plurality of running average filters arranged in a cascade (i.e., serial) fashion. The filter can be constructed using significantly fewer independent component parts for a given level of pass band and stop band performance criteria, as compared with a conventional finite impulse response (FIR) filter. The filter is thus ideally suited for implementation with very large scale integration (VLSI) technology, and in a wide variety of electronic devices where high speed digital filtering is required.

Abstract: A direct digital radio having a high speed RF front end in communication with an antenna, and a radio subsystem that can be configured to form a multi-channel, full duplex transceiver system. The high speed RF front end provides a digital signal to the radio subsystem. Each transceiver includes a waveform processing subsystem that makes use of a linear, phase-B cubic spline interpolating finite impulse response (IFIR) filter for filtering the received RF signal substantially entirely in the digital domain. The linear phase-B, cubic spline IFIR filter requires significantly fewer hardware components than traditional FIR filters and is ideally suited for implementation using Very Large Scale Integration (VLSI) technology.

Abstract: An optical sensor system uses a light source which outputs light at a plurality of wavelengths which vary with time in a manner such that only one wavelength is output at any one point in time; and a transducer which modulates light at each wavelength in a manner indicative of the parameter (for example, position or temperature) begin sensed. The transducer's output is, therefore, an optical signal in which the modulated intensity varies with time since only one wavelength is output at any one point in time. Because only a single wavelength is output at any one time, there is no need for an optical demultiplexer and detector array. Only a single detector is needed.

Abstract: A technique is disclosed for optically trimming a sensor (10) to account for manufacturing variations in the losses of the sensor. As a result, the sensor can be used interchangeably, without requiring adjustment of the processing system (12) the sensor is used with. More particularly, in one embodiment, variably transmissive optical filters 72 and 74 are positioned inside the sensor to effectively alter or standardize the losses of the sensor. Various other arrangements, including the use of variably reflective mirrors, wavelength selective elements, blocking elements, and path adjustment elements, are also described in which the characteristics of the sensor's optical paths are altered.