Abstract: Disclosed is a system and method for receiving and processing a plurality of GNSS signals in a geo-location application to determine location, orientation and/or motion characteristics of a body on which the GNSS signal processing system is located. The system and method provide for precise synchronization of measurements of various signals and data associated with the GNSS signal processing system (including GPS systems), and provide for flexible configuration and allocation of resources used to receive and process GNSS signals to minimize power consumption and maximize efficiency and accuracy of the GNSS signal processing system. The flexibility of the system and method further provide for the scaling of one hardware system to address situations in which more or fewer antennas are employed, in which more or fewer data processing paths are needed, and in which the system is employed to determine various combinations of location, orientation, and motion characteristics.

Abstract: A digital communications system (10) employs a rotationally invariant phase point constellation (80, 80′, 80″) in a modulator (12) thereof and a corresponding carrier phase acquisition phase locked loop (56, 66, 74, 76, 78) in a demodulator (14) thereof. The phase point constellation (80) is rotationally invariant and the demodulator (14) is able to achieve carrier phase synchronization due at least in part to the inclusion of phase point voids (94) positioned in the phase point constellation (80, 80′, 80″). Pragmatic encoding is employed with differential encoding (28, 64) only on non-convolutionally encoded bits. The phase point constellation (80, 80′, 80″) provides identical codes for convolutionally encoded bits (30) of phase points (84) having equal magnitude that are rotated 90°, 180° and 270° degrees from one another. Specific constellations of 256, 64 and 16 points are disclosed.

Abstract: A digital communications modulator (10) includes a low speed IC (12) which performs encoding, symbol generation, pulse shaping, interpolation, linearization, and small amounts of frequency tuning. A complex, baseband digital communications signal (34) is output from the low speed IC (12) as a plurality of parallel streams of digital words. In a digital tuner 14 which includes a high speed IC (20), these parallel streams are digitally combined and digitally up-converted to an IF digital data stream (68) that may have a center frequency many times the baud rate. The high speed IC (20) also converts the digital stream to a broadband analog signal (40). The broadband analog signal (40) is processed through an analog band pass filter (42) that removes spectral images, reduces quantization errors, and limits the bandwidth approximately to the baud rate.