Abstract: A digital data system (100) provides 1-D, 2-D and 3-D capability and multi-band channel capability. Improved filter banks are created by generating a filter bank having an analysis portion and synthesis portion and obtaining wavelet coefficients (302) for each portion. The wavelet coefficients are expressed in a format capable of canonical signed digit (CSD) representation, such as integers (302). The canonical signed digit (CSD) representation is controlled by a value, N, selected to control resolution of the CSD coding. Optimized CSD-coded wavelet coefficients are used as filters for data signals (318).

Abstract: An encoder (300) selects (702, 1302, 1304,1306,1308) one or more subsets of spatially or temporally correlated transformed data coefficients, on the basis of the significance of each subset in representing the data. The encoder (300) and a complementary decoder (400) may be applied to wavelet transform encoded images (500). The encoder (300) may be implemented on a wireless to Internet gateway server (108), in order to reduce byte size of encoded images (500) sent through a wireless network (112), and reduce the amount of processing that must be performed by a wireless device (118) to decode an image or other data. The decoder (400) and/or encoder (300) may be implemented on the wireless device (118).

Abstract: A digital data system (100) provides 1-D, 2-D and 3-D capability and multi-band channel capability. Improved filter banks are created by generating a filter bank having an analysis portion and synthesis portion and obtaining wavelet coefficients (302) for each portion. The wavelet coefficients are expressed in a format capable of canonical signed digit (CSD) representation, such as integers (302). The canonical signed digit (CSD) representation is controlled by a value, N, selected to control resolution of the CSD coding. Optimized CSD-coded wavelet coefficients are used as filters for data signals (318).

Abstract: A digital data system (100) provides 1-D, 2-D and 3-D capability and multi-band channel capability. Improved filter banks are created by generating a filter bank having an analysis portion and synthesis portion and obtaining wavelet coefficients (302) for each portion. The wavelet coefficients are expressed in a format capable of canonical signed digit (CSD) representation, such as integers (302). The canonical signed digit (CSD) representation is controlled by a value, N, selected to control resolution of the CSD coding. Optimized CSD-coded wavelet coefficients are used as filters for data signals (318).

Abstract: An encoder (300) selects (702, 1302, 1304,1306,1308) one or more subsets of spatially or temporally correlated transformed data coefficients, on the basis of the significance of each subset in representing the data. The encoder (300) and a complementary decoder (400) may be applied to wavelet transform encoded images (500). The encoder (300) may be implemented on a wireless to Internet gateway server (108), in order to reduce byte size of encoded images (500) sent through a wireless network (112), and reduce the amount of processing that must be performed by a wireless device (118) to decode an image or other data. The decoder (400) and/or encoder (300) may be implemented on the wireless device (118).

Abstract: An encoder (300) selects (702, 1302, 1304, 1306, 1308) one or more subsets of spatially or temporally correlated transformed data coefficients, on the basis of the significance of each subset in representing the data. The encoder (300) and a complementary decoder (400) may be applied to wavelet transform encoded images (500). The encoder (300) may be implemented on a wireless to Internet gateway server (108), in order to reduce byte size of encoded images (500) sent through a wireless network (112), and reduce the amount of processing that must be performed by a wireless device (118) to decode an image or other data. The decoder (400) and/or encoder (300) may be implemented on the wireless device (118).

Abstract: A method for generating a wavelet filter provides improved selectivity with minimal computational intensity in digital data systems (300,400). The process begins by generating an initial wavelet formed of low pass and high pass analysis filter bank (302). The next steps include obtaining an upper triangular matrix which, when multiplied by the initial wavelet, produces a product retaining the symmetry and enhancing the number of zero moment(s) of the initial wavelet (304); and obtaining a lower triangular matrix which, when multiplied by the initial wavelet, produces a product retaining the symmetry and the zero moment of the initial wavelet (306). By multiplying the upper and lower triangular matrices with the initial wavelet, an updated wavelet filter with improved selectivity is produced (308, 318).

Abstract: A biasing network (2) including a MOS transistor (12) provides a biasing voltage (Vy) to bias a bipolar voltage amplifier (4) having a base emitter voltage (V.sub.BE) of an opposite temperature coefficient from the biasing network (2). A summing node (17) sums the biasing voltage (Vy) and the base emitter voltage (V.sub.BE) to provide an overall low temperature coefficient to provide a constant output voltage (Vx) for the amplifier (4) over temperature.

Abstract: A crystal reference frequency is characterized by determining the compensation signal variations of a compensation signal over temperature for corresponding signal characterization words. The frequency shift variations of the crystal over temperature are determined and the temperature at which the inflection point of the crystal occurs is found. An inflection point characterization word is found which matches the temperature at which the inflection point of the crystal occurs to the temperature at which the inflection point of the compensation signal occurs. The frequency variations of the crystal are correlated to the compensation signal variations and a signal characterization word is selected which substantially minimizes the frequency variations of the crystal over temperature.

Abstract: A current bias generator (10) with a low temperature coefficient sums the currents (13 and 16) from a bipolar current generator (12) and a MOS current generator (14) having opposite temperature coefficients to provide a low temperature coefficient bias current.