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    DIGITALLY COMPENSATED DIRECT CONVERSION RECEIVER
    32.
    发明专利
    DIGITALLY COMPENSATED DIRECT CONVERSION RECEIVER 未知

    公开(公告)号：CA2208850A1

    公开(公告)日：1996-07-04

    申请号：CA2208850

    申请日：1995-12-19

    Applicant: ERICSSON TELEFON AB L M

    Inventor： SALLENHAG MARTIN ,  GUSTAFSSON KJELL ,  ISBERG MARTIN ,  WENDELRUP HEINO ,  LINDQUIST BJOERN

    IPC: H04L27/38 ,  H03D3/00 ,  H04B1/10 ,  H04B1/22 ,  H04B1/26 ,  H04B1/30 ,  H04L27/14 ,  H04L27/227 ,  H04L27/233 ,  H04L1/20 ,  H04Q7/20

    Abstract: A digitally compensated direct-conversion receiver includes devices for generating digital samples of a base-band in-phase signal and a base-band quadrature signal and for detecting the presence of a second-order product signal produced by an amplitude-modulated interfering signal. Also, the apparatus comprises a device for digitally compensating the digital samples by removing the second-order product signal, thereby producing compensated digital samples. In one method of digitally compensating samples of an information signal quadrature-modulating a carrier signal, estimated samples of a second-order product from a switched carrier signal are formed by averaging the digital samples during two time periods and by determining a time of ramps in the in-phase and quadrature signals that occur between the time periods due to the interfering signal. The digital samples may be differentiated and the results smoothed in determining the time of the ramps. In another apparatus, the estimated samples of the second-order product signal are produced by a device for averaging a square of a difference between respective digital samples of the in-phase signal and the quadrature signal, thereby determining an amplitude of the amplitude-modulated carrier signal, and a device for combining the amplitude and the digital samples, thereby generating the estimated samples.

    34.
    发明专利
    未知

    公开(公告)号：DE69833184T2

    公开(公告)日：2006-07-20

    申请号：DE69833184

    申请日：1998-01-13

    Applicant: ERICSSON TELEFON AB L M

    Inventor： MANNERSTRLE JACOB ,  ISBERG MARTIN ,  LINDQUIST BJOERN ,  CARLSSON TORSTEN ,  HAGBERG HANS ,  JAKOBSSON PETER ,  KUENKEL PETER ,  GUSTAFSSON KJELL

    IPC: H04B1/26 ,  H03D3/00 ,  H03D7/16 ,  H04B1/40

    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 occurring on one input (108), mixing is performed from the RF range directly to the baseband frequency range. For radio signals occurring 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.

    37.
    发明专利
    未知

    公开(公告)号：DE69915342T2

    公开(公告)日：2005-01-13

    申请号：DE69915342

    申请日：1999-11-26

    Applicant: ERICSSON TELEFON AB L M

    Inventor： ATARIUS ROOZBEH ,  ERIKSSON H KAN ,  PALENIUS TORGNY ,  CARLSSON TORSTEN ,  GUSTAFSSON KJELL ,  OESTBERG CHRISTER

    IPC: H04B1/7093 ,  H04B1/7115 ,  H04B7/08 ,  H04B1/707

    Abstract: A searcher uses an input signal, and for example, a matched filter to generate a first set of candidate paths. A selector uses the input signal and the first set of candidate paths to generate a second set of paths. The second set of paths is used to configure the fingers of a RAKE receiver. According to one aspect of the invention, the first set of candidate paths contains M paths, and the second stage uses M correlators to generate a set of M correlation values. The second stage uses the M correlation values to select N paths that are used to configure the N fingers of the RAKE receiver. According to another aspect of the invention, the first set of candidate paths contains M paths, and the second stage uses a multiple of M correlators to track the M paths and generate a set of M estimates. The second stage uses the M estimates to select N paths that are used to configure the N fingers of the RAKE receiver. According to another aspect of the invention, the selector can generate new sets of N paths while the searcher is either active or inactive. The receiver can use a quality signal or a counter to notify the searcher and/or the selector to generate new sets of paths. The selector decreases the need to continuously run the matched filter. The receiver can re-configure the fingers without having to search for new paths. The receiver can also find paths that are uncorrelated and less susceptible to fading.

    Searching for signals in a communications system
    40.
    发明专利
    Searching for signals in a communications system 未知

    公开(公告)号：AU2355902A

    公开(公告)日：2002-04-15

    申请号：AU2355902

    申请日：2001-09-25

    Applicant: ERICSSON TELEFON AB L M

    Inventor： CARLSSON TORSTEN ,  GUSTAFSSON KJELL ,  ATARIUS ROOZBEH ,  ERIKSSON HAKAN ,  OSTBERG CHRISTER ,  PALENIUS TORGNY

    IPC: H04B1/7075 ,  H04B1/712 ,  H04B1/707

    Abstract: A method and system enables matched filters of a CDMA system to be simplified using a two stage search. A course stage and a fine stage jointly produce the location(s) of received signal path-rays. In a first stage, an oversampled digital signal is decimated, and the decimated signal is applied to a matched filter to eventually produce an approximate location. In a second stage, the oversampled signal is shifted based on the determined approximate location and then correlated to a generated code, and a more-exact location is selected from the outputs of the correlations. Alternatively, a shifted version of the generated code is correlated to the oversampled signal, and the more-exact location is selected from the outputs of those correlations.

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