Siemens Aktiengesellschaft

Ntt Docomo, Inc.

Technische Universitat Munchen

Technische Universitaet Muenchen

Josef A Nossek

Wolfgang Utschick

Guido Dietl

Manuel Stein

Christian Guthy

Sebastian Theiler

Leonardo Gomes Baltar

Gerhard Bauch

Berthold Lankl

Georg Sebald

Hermann Betzl

Israa Slim

Amine Mezghani

Klaus Boshold

Pedro Tejera

Bernhard Lehmeyer

Michael Joham

Pedro Tejero

The disclosure refers to a synthesis filter bank, comprising: a transform module which is configured to receive a plurality of input signals, transform the plurality of input signals, and output a plurality of transformed signals, a plurality of filter modules, which are coupled to the transform module, and wherein each filter module of the plurality of filter modules is configured to receive two transformed signals from the transform module, process the two received transformed signals and output two processed signals, and a parallel-to-serial module which is coupled to the plurality of filter modules and which is configured to receive the processed signals from the plurality of filter modules, combine the received processed signals and output a combined signal. Furthermore, an analysis filter bank, a filter bank and methods for operating a synthesis filter bank and for operating an analysis filter bank are disclosed.

Filter banks and methods for operating filter banks

An electronic amplifier for amplifying an input signal has a branching node, a supply branch, a balance branch, an auxiliary branch and a load branch. All of the branches are connected in parallel to each other relative to the branching node and a reference potential. The supply branch supplies a DC voltage to the branching node. The balance branch absorbs and/or storing electric energy. A current supply device supplies a DC current. The control switch, the current valve and the current source are in different branches. The control switch, in a pass current state, establishes a current flow from the supply branch into either the auxiliary branch or the balance branch. In the block current state, current flows from the current supply device to the balancing device. The supply, balance and auxiliary branches provide an amplified signal to the load, controlled only by the input signal at the control switch.

Electronic amplifier for amplifying an input signal

The present invention relates to a method of determining a distance or location of a remote device or reflector, the method comprising: receiving a signal from a remote signal transmitter associated with or contained in or attached to the remote device; estimating a first propagation delay associated with the received signal, wherein the first propagation delay represents a first candidate for a correct propagation delay; deriving a relationship between the first candidate and one or more other candidates for a correct propagation delay from the received signal; determining a plurality of other candidates for a correct propagation delay based on said relationship; generating a likelihood histogram based on said candidates for a correct propagation delay; selecting a propagation delay from said candidates based on the likelihood histogram; and determining a distance or location of the remote device or reflector using the selected propagation delay.

Ranging method and apparatus

A method is provided for demodulation of an analog receive signal carrying information, wherein a number of more than two analog signals is formed from the receive signal in separate channels such that the receive signal is multiplied in each case by a period function, the phase thereof respectively differing in the channels, and wherein the multiple signals are each low-pass filtered.

Method for demodulation and demodulator

A spatial sub-channel selection and pre-coding apparatus for being operative in a first communication device, the first communication device being adapted for communicating with a second and a third communication device using MIMO (Multiple-Input-Multiple-Output) radio channels, a first MIMO radio channel extending between the first communication device and the second communication device having at least one spatial sub-channel, a second MIMO radio channel extending between the first communication device and the third communication device having at least one spatial sub-channel, wherein one of the first MIMO radio channel or the second MIMO radio channel has at least two spatial sub-channels.

Spatial sub-channel selection and pre-coding apparatus

Subchannel allocation apparatus for allocating subchannels of a MIMO radio channel to a plurality of users, the MIMO radio channel having a first number of subchannels, each subchannel having a transmission capacity. The subchannel allocation apparatus includes a subspace determiner for determining a subspace of the MIMO radio channel, the subspace having a second number of subchannels, the second number being lower than the first number and each subchannel of the second number of subchannels having a higher transmission capacity than the subchannel with the lowest transmission capacity of the first number of subchannels. The subchannel allocation apparatus further includes a subchannel allocator responsive to the subspace determiner for allocating a subchannel from the second number of subchannels of the subspace to a user based on an allocation metric.

Subchannel allocation apparatus

According to the invention, a base station has an antenna device with a plurality of antenna elements and is connected to a subscriber station via a radio interface. The direction of incidence, the attenuation and the delay times of connection paths used for beam forming for signal sections for channel estimation purposes are determined from the transmissions of the other radio station in a known manner. The beam-forming vector for the transmit signal is constant during these signal sections for channel estimation purposes, for which the radio station can estimate a reception characteristic of the other radio station. Outside the signal sections for channel estimation, a symbol-specific beam-forming vector is determined which takes into account variable symbol-related properties of the transmit signal (for example correlation properties of CDMA codes) which are not constant during a time slot but rather vary from symbol to symbol.

Beam shaping method for the downlink for base stations in radio communication systems

A combiner circuit employs the maximum power method, in which the phase of one of the signals is varied such that the power of the aggregate signal (main and diversity) is varied such that the power of the aggregate subsequently formed is optimally high. In order to improve this combining method that becomes less and less efficient with increasing bandwidth and number of steps of signals, particularly given selective fading, it is provided that the combiner circuit contains a control circuit for the combination phase, the control circuit being composed of a maximum power control circuit and of two preceding, supplementary circuits for varying the amplitudes of the main and diversity signals. The amplitude variation of the main and diversity channel spectrum occurs in such a fashion that the signal spectra are split in the appertaining branches of the two supplementary circuits by respective identical bandpass filters for the lower spectrum half and the upper spectrum half, the powers of the sub-bands are measured at the outputs of the bandpass filters and both sub-bands are set to approximately identical values.

Combiner circuit in space-diversity reception

An adaptive frequency range equalizer for digital radio relay systems which require adaptive frequency range equalizers which have coefficients that are adjustable. That are different possibilities for setting the coefficients of the transversal filter in such equalizers in a manner such that the transmission function of the transversal filter is either of the minimum phase type (mp), or the linear phase type (lp) or the non-minimum phase type (mnp). The invention discloses a method and apparatus for obtaining either of the three transmission functions for the transversal filter.

Adapter frequency range equalizer for digital radio relay systems

An adaptive transverse equalizer formed of delay elements, control elements and summers, and which is constructed in accordance with a serial-in/parallel-out or parallel-in/serial-out concept. Such an equalizer should be improved such that, given a simple structure, it exhibits a high equalizing performance and is particularly suitable for multi-stage digital radio link systems. For this purpose, an equalizer is provided as a linear transverse equalizer and having (n-1) positive and m negative coefficients set in accordance with a zero-forcing algorithm. A linear transverse filter is provided which supplies at least one additional, positive coefficient following upon an access region of the linear transverse filter and whose loop transit time corresponds to n-times or (n+i) times a symbol period.

Adaptive transverse equalizer

An electrical filter circuit for processing analog sampling signals consists of N+1 capacitors interconnected to cyclically circulate N signal charges, the capacitors all being of approximately the same size, and interconnected with an operational amplifier. A plurality of switches are employed, controlled by a clock signal having N+1 phases. Phase controlled switches supply an input signal to the input of the operational amplifier, and provide an output from the filter circuit.

Electrical filter circuit for processing analog sampling signals

Spectrum-converting digital filters are employed for quadrature amplitude modulation. Given the method of the invention, the frequency of the two carrier oscillations residing at 90.degree. relative to one another amounts to one-fourth the sampling frequency and, in addition, their phase positions relative to the sampling times is selected such that every second sample of both carrier oscillations is alternately zero.

Method for digital quadrature amplitude modulation

A switched-capacitor filter circuit having at least one simulated inductor and having an operational amplifier with a capacitor interconnected between its output and inverting input and a non-inverting input connected to a reference potential has a switch leading from the inverting input of the amplifier to a first circuit node from which a first capacitor is connected to the reference potential and also from which a second switch leads to a second circuit node from which another capacitor is connected to the reference potential, and has a third switch leading from the second circuit node to the inverting input of the amplifier and a fourth switch connected between the output of the amplifier and the second circuit node and a fifth switch connected to an input terminal. Each of the switches is controlled by one of a series of sequential non-overlapping clock pulse voltages with the first and fifth switches being simultaneously closed followed by sequential closing of the second, third and fourth switches.

Switched-capacitor filter circuit having at least one simulated inductor

An easily integratable switched-capacitor filter circuit which can be employed to simulate a parallel resonance circuit has an operational amplifier having an inverting input connected to a first circuit node through a first switch, a capacitor interconnected between the first circuit node and a reference potential, a third switch interconnected between the first circuit node and a second circuit node, a capacitor interconnected between the second circuit node and the reference potential, a third switch interconnected between the second circuit node and the output of the operational amplifier, a fourth switch interconnected between the output of the operational amplifier and the first circuit node, and a fifth switch interconnected between the first circuit node and a non-grounded input terminal. The switches are respectively operated by four sequential non-overlapping clock phases such that the third and fifth switches are closed during the first clock phase, the first switch is closed during the second clock phase, the fourth switch is closed during the third clock phase, and the second switch is closed during the fourth clock phase.

Switched-capacitor filter circuit having at least one simulated

A switched-capacitor filter circuit having at least one simulated inductor and having a resonance frequency which is one-sixth of the sampling frequency as pulse-controlled switches co-operatively operable for connecting a first capacitor to a pair of input terminals during a first clock phase and simultaneously connecting a second capacitor to the output of an inverting integration circuit, followed by discharge of the first capacitor to a capacitor in the integration circuit during a second clock pulse phase, followed by a third clock pulse phase during which the first capacitor is charged from the output of the integration circuit and the second capacitor is simultaneously connected to the pair of input terminals and during a fourth clock pulse phase the second capacitor discharges to the capacitor in the integration circuit.

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Iffeldorf, Germany

Josef A Nossek