Abstract: The wireless communication between a base station and a mobile device is frequently based on time division multiple access methods with time slots, some of which are provided for control information. A common time base must be used for this. Since each mobile device has its own time base, it must first of all detect and correct deviations from the time base of the base station. However, the radio signals have unknown and variable transit times. In order to improve the synchronisation of a mobile device with the base station, a mobile device transmits a first synchronisation signal to the base station at a time which, according to its time base, lies in a time slot for control information.

Abstract: For radio transmission via OFDM (Orthogonal Frequency Division Multiplex) and TDMA (Time Division Multiple Access), it is important to have at the receiver the exact carrier frequency, and further to perform time synchronization. For time synchronization and simultaneous detection of a carrier frequency offset, a complex-valued synchronization sequence such as e.g. a Zadoff-Chu-sequence is transmitted twice: first in its original version and then, after a predefined time span, in its complex conjugate version. At the receiver, the two corresponding correlation maxima are detected by cross-correlation, and the time span between the maxima is measured. The measured time span is compared to the predefined time span and a time offset is determined. The time offset can be used to improve the synchronization accuracy and to determine the carrier frequency offset.

Abstract: When an OFDM radio system which uses a wide frequency band is interfered with by another narrow-band radio system, the interference can frequently be compensated but the transmission quality decreases drastically. Thus, narrow-band interferers in an OFDM radio system are determined according to the invention whereby none of the subscribers of the radio system transmits in a defined time slot or scan slot but all switch at the same time into the receiving mode. If there is interference (P1, P2), it is detected in this time slot. Countermeasures are taken individually in all the mobile devices, in particular the detection of the frequency and strength of the narrowband interference (P1, P2) and the configuration of a flexible notch filter (140) in the time range to the detected frequency and strength. The scanned received signal (RXS) is then filtered in the time range, i.e. before the FFT (120) and the OFDM channel estimation (130) by the correspondingly configured notch filter (140).

Abstract: A method for operating at least one mobile radio device that includes a transmitter, a slot for receiving a power supply unit, and a control unit for controlling operation of the transmitter depending on the radio parameters and/or configuration data. Radio parameters and/or configuration data are transferred to a memory of the power supply unit. The power supply unit is inserted into the slot. Operation of the transmitter is controlled by the control unit based on the radio parameters and/or configuration data that are stored in the power supply unit.

Abstract: A method of low-latency audio transmission in a mobile communications network utilizing first data frames or subframes encoded according to a first format and shorter second data frames encoded in another second format for audio data. An audio transmission system includes a terminal, a base station, and an audio receiver. The terminal transmits via an uplink audio data that are encoded in the second format and other data that are encoded in the first format. The audio receiver directly receives the audio data transmitted via the uplink. The encoding/decoding of the audio data of one of the second data frames is influenced by other audio data of the same second data frame but not by audio data of another second data frame. Audio transmission from the terminal to the audio receiver is effected in the allocated time slots and frequencies in a waveform in conformity with the mobile communications network.

Abstract: A method for operating at least one mobile radio device that includes a transmitter, a slot for receiving a power supply unit, and a control unit for controlling operation of the transmitter depending on the radio parameters and/or configuration data. Radio parameters and/or configuration data are transferred to a memory of the power supply unit. The power supply unit is inserted into the slot. Operation of the transmitter is controlled by the control unit based on the radio parameters and/or configuration data that are stored in the power supply unit.

Abstract: A wireless microphone and/or in-ear monitoring system having at least one first mobile device for wirelessly transmitting first audio signals. The system also has at least one base station for wirelessly receiving the first audio signals transmitted by the mobile device. The wireless transmission is based on an orthogonal frequency-division multiplexing transmission (OFDM) during a time-division multiple access (TDMA) time slot. Each wireless microphone occupies at least one slot within 2 ms. Each of the TDMA frames has a plurality of slots which respectively have precisely one OFDM symbol. Accordingly, precisely one OFDM symbol is transmitted in each TDMA slot. During a time slot made available in accordance with the TDMA, a transmission is effected on the basis of an OFDM method. The TDMA frame length is so short as a latency of <4 ms is required for professional audio transmission, for example in the case of wireless microphone systems.

Abstract: A wireless microphone and/or in-ear monitoring system having a clock master prescribing a wordclock, and a clock slave to be synchronized to the wordclock. Between the clock master and the clock slave is a digital wireless transmission link which digitally transmits synchronization signals and audio signals. The clock master has a clock reference prescribing a first sample clock, and a first timer. A first phase of the first clock signal is detected after expiry of the first timer and is wirelessly transmitted to the clock slave, which has a second timer. After expiry of the second timer, a second phase of the second clock signal of the clock slave is detected and compared to the wirelessly transmitted first phase. The difference between the first and second phases is used as an input value as a control unit in the clock slave. The control unit adjusts an adjustable sample clock of the clock slave to correspond to the first clock.

Abstract: A method of low-latency audio transmission in a mobile communications network utilizing first data frames or subframes encoded according to a first format and shorter second data frames encoded in another second format for audio data. An audio transmission system includes a terminal, a base station, and an audio receiver. The terminal transmits via an uplink audio data that are encoded in the second format and other data that are encoded in the first format. The audio receiver directly receives the audio data transmitted via the uplink. The encoding/decoding of the audio data of one of the second data frames is influenced by other audio data of the same second data frame but not by audio data of another second data frame. Audio transmission from the terminal to the audio receiver is effected in the allocated time slots and frequencies in a waveform in conformity with the mobile communications network.

Abstract: A wireless microphone and/or in-ear monitoring system having at least one first mobile device for wirelessly transmitting first audio signals. The system also has at least one base station for wirelessly receiving the first audio signals transmitted by the mobile device. The wireless transmission is based on an orthogonal frequency-division multiplexing transmission (OFDM) during a time-division multiple access (TDMA) time slot. Each wireless microphone occupies at least one slot within 2 ms. Each of the TDMA frames has a plurality of slots which respectively have precisely one OFDM symbol. Accordingly, precisely one OFDM symbol is transmitted in each TDMA slot. During a time slot made available in accordance with the TDMA, a transmission is effected on the basis of an OFDM method. The TDMA frame length is so short as a latency of <4 ms is required for professional audio transmission, for example in the case of wireless microphone systems.

Abstract: A wireless microphone and/or in-ear monitoring system having at least one first mobile device for wirelessly transmitting first audio signals. The system also has at least one base station for wirelessly receiving the first audio signals transmitted by the mobile device. The wireless transmission is based on an orthogonal frequency-division multiplexing transmission (OFDM) during a time-division multiple access (TDMA) time slot. Each wireless microphone occupies at least one slot within 2 ms. Each of the TDMA frames has a plurality of slots which respectively have precisely one OFDM symbol. Accordingly, precisely one OFDM symbol is transmitted in each TDMA slot. During a time slot made available in accordance with the TDMA, a transmission is effected on the basis of an OFDM method. The TDMA frame length is so short as a latency of <4 ms is required for professional audio transmission, for example in the case of wireless microphone systems.

Abstract: A wireless microphone and/or in-ear monitoring system having a clock master prescribing a wordclock, and a clock slave to be synchronized to the wordclock. Between the clock master and the clock slave is a digital wireless transmission link which digitally transmits synchronization signals and audio signals. The clock master has a clock reference prescribing a first sample clock, and a first timer. A first phase of the first clock signal is detected after expiry of the first timer and is wirelessly transmitted to the clock slave, which has a second timer. After expiry of the second timer, a second phase of the second clock signal of the clock slave is detected and compared to the wirelessly transmitted first phase. The difference between the first and second phases is used as an input value as a control unit in the clock slave. The control unit adjusts an adjustable sample clock of the clock slave to correspond to the first clock.

Abstract: A wireless microphone and/or in-ear monitoring system having at least one first mobile device for wirelessly transmitting first audio signals. The system also has at least one base station for wirelessly receiving the first audio signals transmitted by the mobile device. The wireless transmission is based on an orthogonal frequency-division multiplexing transmission (OFDM) during a time-division multiple access (TDMA) time slot. Each wireless microphone occupies at least one slot within 2 ms. Each of the TDMA frames has a plurality of slots which respectively have precisely one OFDM symbol. Accordingly, precisely one OFDM symbol is transmitted in each TDMA slot. During a time slot made available in accordance with the TDMA, a transmission is effected on the basis of an OFDM method. The TDMA frame length is so short as a latency of <4 ms is required for professional audio transmission, for example in the case of wireless microphone systems.

Abstract: There is provided a method of frequency assignment of wireless radio audio transmission systems having a plurality of wireless transmitters and at least one wireless receiver. The wireless transmitters can represent first wireless transmitters which in the switched-on condition can approach another wireless transmitter below an established minimum spacing and second wireless transmitters which in the switched-on condition cannot approach below the minimum spacing. The wireless transmitters serve for example to transmit an audio signal wirelessly to the at least one wireless receiver. The transmission frequencies of the first wireless transmitters are assigned having regard to possible intermodulation effects. The transmission frequencies of the second wireless transmitters are assigned having regard to the relative spatial distances of the second wireless transmitters relative to each other.

Abstract: There is provided a method of frequency assignment of wireless radio audio transmission systems having a plurality of wireless transmitters and at least one wireless receiver. The wireless transmitters can represent first wireless transmitters which in the switched-on condition can approach another wireless transmitter below an established minimum spacing and second wireless transmitters which in the switched-on condition cannot approach below the minimum spacing. The wireless transmitters serve for example to transmit an audio signal wirelessly to the at least one wireless receiver. The transmission frequencies of the first wireless transmitters are assigned having regard to possible intermodulation effects. The transmission frequencies of the second wireless transmitters are assigned having regard to the relative spatial distances of the second wireless transmitters relative to each other.

Abstract: There is provided a stationary analog FM-receiver for receiving analog wirelessly transmitted FM-audio signals from at least one mobile unit. The frequency has a frequency demodulator (FDM) for demodulating the received FM-audio signals. The FM-receiver further has a link quality unit (LQE) for determining a link quality for the wireless transmission of the FM-audio signals. The link quality unit (LQE) has a high-pass filter (HP) with a limit frequency for high-pass filtration of an output signal of the frequency demodulator (FDM) and a power determining unit (SE, LBE) for determining the power of the output signal of the high-pass filter (HP). The limit frequency of the high-pass filter (HP) lies in the region of between 20 kHz and 80 kHz, in particular in the region of between 50 kHz and 80 kHz.

Abstract: A wireless communication system is provided having a transmitter, having a modulation unit for performing a frequency shift keying modulation wherein an output of the modulation unit is bundled into data blocks. The communication system furthermore comprises a cyclic prefix adding unit for adding a cyclic prefix (CP) into each data block of an output of the modulation unit.