Siemens Aktiengesellschaft

Rohde and Schwarz Gmbh & Co. Kg

Siemens Aktiengesell Schaft

Laboratorium Prof. Dr. Rudolf Berthold

Laboratorium Prof. Dr. Rudolf Berthold Gmbh & Co.

Hermann-Josef Eul

Burkhard Schiek

Norbert Metzner

In a homodyne receiver for the reception of a carrier frequency signal modulated with a low-frequency signal, the sensitivity of the detection of the low-frequency signal is enhanced by two auxiliary modulations before the conversion into the base band. The auxiliary signal utilized for an auxiliary modulation of the local oscillator signal and the supplemental signal employed for an auxiliary modulation of the carrier frequency signal comprise frequencies that can be technologically governed and with economic outlay and enable the simple decoupling of the low-frequency signal from the supplemental signal and, thus, an enhancement of the sensitivity of the homodyne receiver. The decoupling is particularly achieved by a band-pass filtering after the conversion of the carrier frequency signal into the base band, this band-pass filtering being tuned to a specific frequency relationship of the auxiliary signal and the supplemental signal. An advantage of the homodyne receiver is of particular economic significance for employment in mass-produced articles, such as in mobile and wireless communication systems.

Method for enhancing the reception sensitivity in homodyne recievers

In a homodyne receiver for the reception of a carrier frequency signal with time-variant carrier frequency, an auxiliary signal is modulated onto the local oscillator signal selected corresponding to the current carrier frequency. A better separation of the local oscillator signals is thereby achieved by a band-pass filtering after the conversion of the carrier frequency signal into the base band. Compared to a homodyne receiver with time-variant carrier frequency but without auxiliary modulation, the RF switch for the selection of the local oscillator signal corresponding to the current carrier frequency can be realized simple and more economical. This advantage of the homodyne receiver is of particular economic significance for employment in mass-produced articles, such as in mobile and wireless communication systems.

Method for reducing spurious reception locations in homodyne receivers

In a method for optimizing the automatic amplifier setting in radio receivers in which information available in a radio station is utilized in a new manner. A prediction about the behavior of the reception power is to be undertaken in the reception station. To this end, the transmission power control of one station and of the variations to be anticipated as a result thereof are involved in the prediction of the anticipated reception power of the other station. This ensues in such a way that a prediction based on knowledge of the transmission power control data is supplied to the automatic gain control (AGC) of the receiver.

Method for optimizing the automatic amplifier setting in radio receivers

A method for merging data streams generated by a plurality of base stations in a cellular mobile radio telephone network upon receipt by each base station of a mobile unit signal transmitted by a mobile unit, wherein each base station routes the mobile unit signal in the form of a stream of data in blocks of data bits, each bit in each block having associated therewith a reliability value generated by its respective base station, the various streams of data generated by the base stations are received at a unification point, and a unified signal is generated out of the various base station streams of data in the form of a composite data stream by selecting each bit thereof from corresponding bits in the various base station streams of data.

Method for merging data streams

In a method of calibrating a network analyzer, in which calibration measurements are performed in succession in a random sequence on several different calibration standards which are linked to the two test ports, the first calibration standard used is a two-port unit which is linked between the two test ports and of which all complex scattering parameters are known, and the further calibration standards used are three one-port units of random, though different, reflection characteristics which are successively linked to one of the two test ports, or are linked in any desired combination to both test ports.

Method of calibrating a network analyzer

A multistage single-sideband shifter composed of N switchable phase shifters connected in cascade, where N is a positive integer greater than 1, each phase shifter being constructed to produce a switchable phase shift and a control unit connected to the phase shifters for switching the phase shifters chronologically successively in a selected sequence into all possible 2.sup.N combinations, for periodically repeating the selected sequence, and for chronologically reversing the selected sequence.

Multistage single-sideband shifter

Methods for establishing the complex measuring capability of homodyne operating network analyzers. Single port as well as two-port measuring devices are treated in which the signal detection takes place by means of a linear mixing process. It is possible to overcome the disadvantage of the homodyne detection process, which does not directly supply information relating to the amplitude and phase of the measurement signal, by measuring arbitrary unknown standards. The required number of different unknown standards depends, among other things, on the complexity of the measuring device used. One of the proposed methods operates without any standards at all. After weighting factors have been determined, complex measuring values can be ascertained and one can then proceed as in the case of a heterodyne network analyzer, i.e. with system error calibration measurements and finally with DUT (device under test) measurements.

Growing community of inventors

Oberschleissheim, Germany

Hermann-Josef Eul