Abstract:
Pipeline A/D-conversion of an analog input signal is performed according to a new and inventive algorithm which generates a Gray coded digital output signal. A pipeline A/D-converter comprises a number of cascaded stages through which the analog input signal is propagated. Each stage generally generates an output bit of the digital output signal, and furthermore processes the pipeline signal. According to the inventive Gray coding algorithm, the output bit generated in a stage determines whether or not the pipeline signal of that stage is inverted. In a pipeling A/D-converter based on the Gray coding algorithm according to the invention, the accumulation of offset errors will generally be very low. Furthermore, the fact that the signal inversion is digitally controlled enables high precision implementations which further improve the performance of the inventive pipeline A/D-converter. In another embodiment of the invention, the Gray coding algorithm is modified to form a second algorithm which makes low device count implementations possible.
Abstract:
A complex switched capacitor filter is formed by selecting (S3) an analog baseband prototype filter with the desired filter characteristics (S2). This prototype is converted (S4) into a corresponding real switched capacitor filter, and finally the real switched capacitor filter is converted (S5) into a complex switched capacitor filter by replacing each element of real filter by a frequency shifted complex counterpart.
Abstract:
A down-converter converts an amplitude modulated high frequency signal into a low frequency or baseband signal. A first mixer (30, 32) mixes the high frequency signal into a composite signal having an in-phase component and a quadrature component. A complex bandpass filter (34) bandwith limits the composite signal into a bandwidth limited signal with an in-phase component and a quadrature component. A second mixer (36, 38) mixes the bandwidth limited signal into an intermediate signal with an in-phase component and a quadrature component, and an adder (40) adds one component of the intermediate signal to the other. A similar up-conventer performs the reverse process.
Abstract:
D/A-conversion of a Gray coded digital input signal is performed according to an inventive recursive Gray code-to-analog conversion algorithm. According to the recursive algorithm, the Gray code bits of the digital input are successively applied in the recursions of the algorithm, one Gray code bit for each recursion, and the analog output signal is generated by recursively updating an intermediate signal. In each recursion, the intermediate signal is selectively inverted in dependence on the particular Gray code bit that is applied in the recursion. The selective inversion of the intermediate signal is an inherent property of the Gray code-to-analog algorithm, and it is a key factor to reduce the accumulation of errors in a D/A-conversion. In a D/A-converter architecture based on the algorithm, the accumulation of offset errors will be low. Furthermore, the fact that the signal inversion is digitally controlled enables high precision implementations, further improving the performance of the D/A-converter. 00000
Abstract:
A complex switched capacitor filter is formed by selecting (S3) an analog baseband prototype filter with the desired filter characteristics (S2). This prototype is converted (S4) into a corresponding real switched capacitor filter, and finally the real switched capacitor filter is converted (S5) into a complex switched capacitor filter by replacing each element of real filter by a frequency shifted complex counterpart.
Abstract:
A base station in a radio communication system uses complex bandpass filters (Φ1, Φ2, ..., ΦN) and down-sampling to channelize a wideband signal containing many channels or channel groups.
Abstract:
The technology downloads and upgrades terminal software of a communications device over-the-air in a efficient and fail-safe manner. The communication device is provided with radio software from a server via a wireless network including a number of access networks. A download is initiated of radio software designed for a first of two different radio access technologies of the communication device. One of the two radio access technologies of the communication device is selected for downloading the software. The radio software is downloaded via the selected available radio access technology. The radio software designed for the first radio access technology is stored in memory.
Abstract:
A down-converter converts an amplitude modulated high frequency signal into a low frequency or baseband signal. A first mixer (30, 32) mixes the high frequency signal into a composite signal having an in-phase component and a quadrature component. A complex bandpass filter (34) bandwidth limits the composite signal into a bandwidth limited signal with an in-phase component and a quadrature component. A second mixer (36, 38) mixes the bandwidth limited signal into an intermediate signal with an in-phase component and a quadrature component, and an adder (40) adds one component of the intermediate signal to the other. A similar up-converter performs the reverse process.
Abstract:
A base station in a radio communication system uses complex bandpass filters and down-sampling to channelize a wideband signal containing many channels or channel groups.