Methods and systems for programmable digital down-conversion
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsBradley John Morris, Lars Johan Thorebäck
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Abstract
A radio communication apparatus operable over a wide range of frequencies including a signal processing device is provided. The device performs an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and digitally processes the digital signal to output a data signal at baseband associated with the selected frequency band.
Claims15
A radio communication apparatus operable over a wide range of frequencies, comprising:
- a signal processing device configured
- to receive an analog signal,
- to perform an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and
- to digitally process said digital signal to output a data signal at baseband associated with said selected frequency band, wherein the signal processing device comprises:
- an analog to digital converter configured to sample the received analog signal at said predetermined sample rate, and to output said digital signal;
- a quadrature demodulator configured to perform quadrature demodulation of the digital signal, and to output a complex signal including a complex data signal and an image of the complex data signal;
- a complex channel selection filter configured to receive the complex signal, and to output a filtered complex signal including only one of the complex data signal or the image of the complex data signal;
- a digital down-sampler configured to receive the filtered complex signal and to generate a down-sampled complex signal that includes one sample out of each group of N sequential samples in the filtered complex signal, where N is an integer number larger than or equal to two and depends on the selected frequency band;
- and
- a baseband tuner configured to receive the down-sampled complex signal, and to output a complex baseband data signal.
A radio communication apparatus operable over a wide range of frequencies, comprising:
- a signal processing device configured
- to receive an analog signal,
- to perform an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and
- to digitally process said digital signal to output a data signal at baseband associated with said selected frequency band
- wherein the signal processing device further comprises:
- an analog to digital converter configured to sample the filtered analog signal at a predetermined sample rate, and to output a sampled digital signal;
- a quadrature demodulator configured to perform quadrature demodulation of the sampled digital signal, and to output a complex signal;
- a polyphase filter configured to filter the complex signal to include a single image in a complex data signal, and to down-sample the filtered complex data signal to output a down-sampled complex signal including one sample out of each group of N sequential samples in the filtered complex data signal, where N is an integer number larger than or equal to two, and depends on the selected frequency band;
- and
- a baseband tuner configured to receive the down-sampled complex signal, and to extract a complex baseband data signal from the down-sampled complex signal.
A method of processing a quadrature modulated analog signal to output a baseband digital data signal, while focusing on a selected frequency band within a wide range of frequencies in a digital signal, comprising:
- selecting the frequency band among a plurality of predetermined frequency bands within an operable frequency range;
- converting at a predetermined sample rate, an analog signal into a digital signal;
- demodulating the digital signal to output a complex digital signal;
- filtering the complex digital signal to include a single image in a complex data signal;
- down-sampling the filtered complex digital signal, to generate a down-sampled complex signal that includes one sample out of each group of N sequential samples in the filtered complex digital signal, where N is an integer number larger than or equal to two, and depends on the selected frequency band;
- and
- extracting a complex baseband data signal from the down-sampled complex signal, wherein one or more of the filtering of the received quadrature modulated signal, the filtering of the complex digital signal, and the extracting of the complex baseband data signal are performed based on operating parameters depending on the selected frequency band.
A method of processing a quadrature modulated analog signal to output a baseband digital data signal, while focusing on a selected frequency band within a wide range of frequencies in a digital signal, comprising:
- converting at a predetermined sample rate, an analog signal into a digital signal;
- demodulating the digital signal to output a complex digital signal;
- filtering the complex digital signal to include a single image in a complex data signal;
- down-sampling the filtered complex digital signal, to generate a down-sampled complex signal that includes one sample out of each group of N sequential samples in the filtered complex digital signal, where N is an integer number larger than or equal to two, and depends on the selected frequency band;
- and
- extracting a complex baseband data signal from the down-sampled complex signal, wherein the down-sampling is performed for values of N that are powers of 2.
Dependencies are inferred from the claim text.