Abstract:
A method and system enable matched filters of a CDMA system to be simplified using a two stage search. A course stage and a fine stage jointly produce the locations(s) of received signal path-rays. In a first stage, an oversampled digital signal (240) is decimated, and the decimated signal (415) is applied to a matched filter (420) to eventually produce an approximate location (460). In a second stage, the oversampled signal (240) is shifted based on the determined approximate location (460) and then correlated to a generated code (440), and a more-exact location is selected from the outputs of the correlations (450). Alternatively, a shifted version of the generated code (440) is correlated to the oversampled signal (240), and the more-exact location is selected from the outputs of those correlations (450).
Abstract:
A technique for improving open loop power control in spread spectrum telecommunications systems is disclosed. In a preferred embodiment, the technique is realized by transmitting at least one first access channel probe for a first message from a mobile station to a base station, wherein the transmission power level of each access channel probe in the at least one first access channel probe is increased until a base station acknowledgment is received for a specific access channel probe of the at least one first access channel probe at a first transmission power level. The first transmission power level is then stored at the mobile station. At least one second access channel probe for a second message is then transmitted from the mobile station to the base station, wherein the transmission power level of an initial access channel probe of the at least one second access channel probe for the second message is based upon the first transmission power level.
Abstract:
A multiple-mode receiver incorporating direct conversion (processing received signals using intermediate frequencies within the same frequency range as the received signal bandwidth) rather than superheterodyne circuitry, allowing receiver hardware components to be re-used rather than replicated for each band. Various embodiments are disclosed in which low pass filters, mixers, quadrature generators, oscillators, and amplifiers are re-used.
Abstract:
A method and system enable matched filters of a CDMA system to be simplified using a two stage search. A course stage and a fine stage jointly produce the locations(s) of received signal path-rays. In a first stage, an oversampled digital signal (240) is decimated, and the decimated signal (415) is applied to a matched filter (420) to eventually produce an approximate location (460). In a second stage, the oversampled signal (240) is shifted based on the determined approximate location (460) and then correlated to a generated code (440), and a more-exact location is selected from the outputs of the correlations (450). Alternatively, a shifted version of the generated code (440) is correlated to the oversampled signal (240), and the more-exact location is selected from the outputs of those correlations (450).
Abstract:
The present invention relates to a receiver device comprising a receiver (104) adapted to receive radio signals in two frequency bands (FB1, FB2). The radio signals in one of the frequency bands (FB1) constitute communication signals for a radio system (AMPS, NMT) having a certain channel spacing, whereas the radio signals of the second frequency band (FB2) constitutes communication signals for a second radio system (PCS1900, DCS1800, GSM) having a second certain channel spacing. The receiver (104) comprises two inputs (108, 11) each intended for a radio system having different frequency bands and channel spacing. For radio signals occuring on one input (108), mixing is performed from the RF range directly to the baseband frequency range. For radio signals occuring on the second input (108) the mixing from the radio frequency range to the baseband frequency range is carried out through an intermediate frequency range. Further the receiver (104) comprises an output (112) intended to deliver baseband signals for both radio systems. The output (112) is connected to a baseband unit which is common to the radio systems. In the baseband unit, among other things, lowpass filtering, detection and neighbouring channel suppression are performed on the received radio signal that has been mixed down to the baseband frequency range.
Abstract:
A receiver having a digital automatic gain control (AGC) circuit is disclosed for use in a cellular communication system, including a Hierarchical Cellular System. The receiver includes a controller which switches between gain control values depending on system operational mode. In this way, the AGC can be optimized for different types of receive processing operations, e.g., traffic reception and measurement of other channels.
Abstract:
A method and apparatus is described for providing a camera accessory to a wireless mobile terminal in a wireless radiocommunication system. The wireless mobile terminal has an image data interface and a physical interface for detachably coupling the camera accessory thereto. One or more frames of image data is captured in the camera accessory and compressed according to one or more compression formats. The captured and compressed frames are transferred to the wireless mobile terminal over the image data interface. The camera accessory does not include a display. Image data is captured in a predetermined format including a CIF format. Still image frames are compressed using a JPEG format and an image stream is compressed using an MPEG format. The captured and compressed frames are transferred to the wireless mobile terminal over the image data interface using respective predetermined formats including RGB CIF, YUV CIF, JPEG, MPEG, and MPEG-4 with CIF to QCIF conversion format. The image data interface includes a wired interface and wherein the camera accessory derives a power supply from the wireless mobile terminal or includes a wireless interface.
Abstract:
A method and apparatus is described for providing a camera accessory to a wireless mobile terminal in a wireless radiocommunication system. The wireless mobile terminal has an image data interface and a physical interface for detachably coupling the camera accessory thereto. One or more frames of image data is captured in the camera accessory and compressed according to one or more compression formats. The captured and compressed frames are transferred to the wireless mobile terminal over the image data interface. The camera accessory does not include a display. Image data is captured in a predetermined format including a CIF format. Still image frames are compressed using a JPEG format and an image stream is compressed using an MPEG format. The captured and compressed frames are transferred to the wireless mobile terminal over the image data interface using respective predetermined formats including RGB CIF, YUV CIF, JPEG, MPEG, and MPEG-4 with CIF to QCIF conversion format. The image data interface includes a wired interface and wherein the camera accessory derives a power supply from the wireless mobile terminal or includes a wireless interface.