Abstract:
In a telecommunications transmitter and receiver two IQ-mixers are operated in 180 degrees phase shift. In both the transmitter and receiver, an input signal is coupled to each IQ-mixer and the output signal of the mixers are combined so as to cancel unwanted error components in each individual output signal. In the transmitter, residual carrier signals are cancelled, and in the receiver, DC-offsets are cancelled. In both, the wanted signals are added, doubling the amplitude of the resultant output signal leading to four times more output power and improved dynamic range.
Abstract:
The application relates to transmission power control in transmission systems, in particular mobile radio systems. One object of the invention is to indicate a way of guaranteeing, compared with the state of the art, improved, in particular dynamic, control of transmission powers within predefinable emitted interference requirements with, in particular, increased efficiency and reduced power consumption. For this purpose, the invention provides for the filtering of an amplified transmission signal to be divided up between a narrower-band tunable pre-filter (4) and a broadband post-filter (10). To perform this operation, a signal-amplification circuit is proposed which comprises a tunable filter (4) which is connected downstream of a power amplifier (2).
Abstract:
The invention relates to a transmitting/receiving apparatus for electromagnetic signals which combines signals transmitted by four transmitters by means of two hybrid and/or broadband combiners. The broadband combiners comprise two filters which define frequency ranges within which the respectively assigned transmitters can transmit. The filters cover in particular a plurality of frequency channels, with the result that synthesizer hopping is possible. The invention furthermore relates to a method for combined synthesizer and baseband hopping which is particularly advantageous for the apparatus according to the invention in order to ensure effective channel utilization.
Abstract:
In an apparatus for controlling the volume of a device's user alert sound based on an analysis of the device's environment, the device (20) emits a signal and receives a resulting reflected signal. A processor (25) measures characteristics such as the amplitude and/or delay of the reflected signal to determine the type of environment in which the communication device (20) is located. The volume of the alert sound is then adjusted based on the type of environment indicted by the characteristics of the reflected signal. For example, if the characteristics indicate a closed environment such as a brief case, the volume is adjusted to a high level, and if the characteristics indicate an open environment such as a desk top, the volume is adjusted to a low level.
Abstract:
Transmission and reception device for a mobile radio base station comprising a plurality of transmission and reception units and hence a plurality of carriers, the transmission and reception units being accommodated in push-in modules and each having a modulator (10), a channel frequency device (19) and an output stage (20). At least some of the push-in modules comprise two full transmission and reception units having a first and a second transmission branch (1, 2). The two transmission branches (1, 2) are connected to a transmission connection (4) via an incorporated hybrid combiner (3) in order to provide two mutually combined carriers in a first mode of operation for relatively high capacity. In a second mode of operation for high output power, the two transmission branches (1, 2) are additionally connected to one another by means of an internal changeover device (25, 26, 27) such that the same transmitted signal is routed at least via the output stages (20) of both transmission branches (1, 2).
Abstract:
There is described a screen-circuit board assembly, comprising: a circuit board (10) having slots (11) with edges (12) and through which insertion portions (21) of the screen (20) extend; at least one spring clamp (1) allocated to the slots (11) and forming a slot cavity space (7), wherein the at least one spring clamp comprises supporting legs (2) and clamp side-walls (3). Each supporting leg (2) is soldered to an associated edge (12) of the slot to which it is allocated. At least one of the clamp side-walls (3) carries at least one spring member (5) in order to clamp and electrically connect the respective insertion portion (21) of the screen (20) to the circuit board (10). A process for the production of such screen-circuit boards is also disclosed.
Abstract:
In an apparatus for controlling the volume of a device's user alert sound based on an analysis of the device's environment, the device (20) emits a signal and receives a resulting reflected signal. A processor (25) measures characteristics such as the amplitude and/or delay of the reflected signal to determine the type of environment in which the communication device (20) is located. The volume of the alert sound is then adjusted based on the type of environment indicted by the characteristics of the reflected signal. For example, if the characteristics indicate a closed environment such as a brief case, the volume is adjusted to a high level, and if the characteristics indicate an open environment such as a desk top, the volume is adjusted to a low level.
Abstract:
The invention proposes a power amplification under variable envelope excitation, wherein an original input signal at least is converted into a phase modulated signal part, at least the phase modulated signal part is fed to an input port of an amplifier unit, the input signal is amplified by dynamically selecting a fixed power supply (PSU 1,PSU 2,PSU 3) for the amplifier unit, and wherein the amplitude content of the original input signal is reconstructed by changing dependent on the respective provided power supply a further controllable input of the amplifier unit, in particular the input power level (P in ) and/or the biasing voltage (U g ) and/or biasing current at the control input of the amplifier unit, during said step of amplifying.