Abstract: A wireless multicarrier transmission method wherein subcarriers of the transmission are adaptively modulated. The fading condition of each subcarrier is detected to generate fading channel profile information. Adaptive loading tables are calculated for lower, standard, and higher modulation schemes. One of the adaptive loading tables is selected and those subcarriers having low fading channel profile information are modulated with the lower modulation scheme, subcarriers having medium fading channel profile information are modulated with the standard modulation scheme, and subcarriers having high fading channel profile information are modulated with the higher modulation scheme.

Abstract: For example in case of an OFDM multicarrier transmission system the transmission characteristics of subcarriers of a multicarrier transmission system using a plurality of antenna elements (3, 3?) can be adjusted. Particularly the power and the phase of the subcarriers can be adapted. To this object the subcarrier frequency channel (2, 2?) characteristics of the multicarrier transmission are detected (11, 11?) at the side of the transmitter (3). The power of each subcarrier is then distributed by a weighting unit (14, 14?). The subcarriers can be further pre-equalized (1, 1?) by dividing the subcarrier signal respectively by the sum of the squared magnitude of the frequency channel characteristics of all subcarrier signals or a frequency characteristic of the selected antenna element (3, 3?).

Abstract: A heterogeneous wireless network topology suited for low-power, short-range and ubiquitous ad-hoc communication. The network topology integrates different wireless transmission technologies, in particular to a wireless sensor network including different node types and communication technologies. The network is highly heterogeneous and can be operated according to the master-slave principle. The nodes can have different wireless communication means tailored to their individual role in the network and other constraints, thus allowing different communication patterns.

Abstract: A pole switch down-converter with symmetric resonator which reduce the non resonating phase to approximately half of the RF carrier period of the modulated signal is proposed. The down-converter comprises a first and second ?/2 resonator for collecting RF energy, wherein a differential RF signal is coupled to the first and second ?/2 resonator, a switching means coupled at one end of the first ?/2 resonator and one end of second ?/2 resonator for connecting the first and second ?/2 resonator, a control means for controlling the switching means, and a detecting means coupled to the first and second ?/2 resonator for detecting the down-converted signal, wherein the control means is adapted to initiate in a down-conversion cycle the switching means to connect the first and second ?/2 resonator for approximate half of the RF carrier period of the modulated signal. With this pole switch down-converter adjacent RF channels can be selected and down-converted by slightly varying the pole switch repetition rate.

Abstract: A receiving apparatus (1) for receiving signals in a digital telecommunication system and a synchronizing method for synchronizing the receiving apparatus (1). The receiving apparatus (1) includes a receiver (2, 3) for receiving a reference symbol having at least two repetition patterns. One of the repetition patterns is phase-shifted in relation to the other. The receiving apparatus (1) is synchronized in the digital telecommunication system using the received reference symbol. The synchronization includes a cross correlation of at least one of the two repetition patterns within a cross correlation window having a predetermined length. In this manner, the performance and the accuracy of a cross correlation peak detection can be enhanced for improved synchronization.

Abstract: Orthogonal Frequency Division Multiplexed transmission and reception using a broadcast burst preamble. The preamble comprises at least one first part (A-FIELD) designed for a coarse frame detection and/or an AGC control, and at least one second part (B-FIELD) following the at least one first part in the time domain and being designed for a timing and frequency synchronization. The at least one first part (A-FIELD) and the at least one second part (B-FIELD) each include Inverse Fast Fourier Transformed (IFFT) frequency domain sequences of complex symbols. The frequency domain sequence of the at least one first part (A-FIELD) is set depending on the frequency domain sequence of the at least one second part (B-FIELD) such that a second autocorrelation peak mainly generated by the at least one second part (B-FIELD) of the preamble is optimized. The sequence of complex symbols of the first part differs from the sequence of complex symbols of the second part in at least one symbol.

Abstract: A data modulation method and a data modulation device and a communication device are disclosed. The present invention relates to the synchronization and training preamble. The reference symbol optimized in order to contain the structure of “IA-A-IA-A-A-IA-A-IA-IA” is allocated to sub-carriers of the OFDM symbol. More specifically, by designing the structure of the preamble of the time domain, distinction from the other communication system can be certainly conducted holding the correctness of the clock synchronization. Also, we have adopted the series having low peak average ratio and dynamic range of sync symbol using the OFDM. Since the generation and the detection processings can be conducted in utilizing the generation device and the detection device of the sync preamble used in the convention system, this system has an advantage in increasing the common use of the LSI chip. We have made the sync series divided into 2 parts A and B before to one B region and made this to have simple construction.

Abstract: The present invention relates to a cellular communication system for wireless telecommunication on the basis of an OFDM scheme, comprising a plurality of base stations B, whereby at least one base station B is allocated to each cell C of the communication system and whereby information communicated from the base stations comprises data parts and pilot parts. The present invention further relates to a method for operating such a cellular communication system. The present invention is characterised in that the frequency reuse factor of the data parts is different from a frequency reuse factor of the pilot parts. Hereby, an optimisation between high capacity and reliable and correct channel estimation on the basis of the pilot parts can be achieved.

Abstract: This proposal describes an optimized synchronization (SYNCH) symbol sequence to be used in transmission systems, which are currently under standardization. The synchronization symbol is constructed using specially designed OFDM (orthogonal frequency division multiplexing) symbols with an optimized sequence, which is mapped onto the modulated subcarriers. The resulting synchronization symbol consists of several repetitions in the time domain. Using the proposed sequence the resulting synchronization symbol achieves a high timing detection and frequency offset estimation accuracy. Furthermore the burst is optimized to achieve a very low envelope fluctuation (low Peak-to-Average Power Ratio) and a very low dynamic range to reduce complexity on the receiver and to save time and frequency acquisition time in the receiver. The proposed sequence is furthermore optimized with respect to all other synchronization symbols that are used to construct the synchronization and training preambles for the BCCH-DLCHs.

Abstract: The present invention relates to a transmission apparatus for transmitting OFDM-signals comprising modulation means 4 for modulating said signals onto a plurality of subcarriers using a OFDM-modulation method, transformation means 5 for transforming said modulated signals into the time domain, and transmission means for transmitting said signals, whereby in said modulation means every M-th subcarrier is modulated, wherein M is an integer and M≧2. The present invention also relates to a corresponding transmission method for transmitting OFDM-signals.

Abstract: The present invention relates to a base station (1, 10, 20) and a mobile terminal (40, 50, 60) as well as a communication method for communicating in a wireless radio communication system. Thereby, the information is transmitted and received in medium access control frames of the communication system, whereby the transmission power of at least a broadcast control channel and a frame control channel in a respective medium access control frame transmitted by a base station is increased after certain time intervals to an increased transmission power level as compared to the transmission power level of other medium access control frames transmitted during said time intervals.

Abstract: A communication device for transmitting and receiving control and user data bursts in a digital telecommunication system. Data bursts including bursts of a first type and bursts of a second type different from the first type, are received, with the first type bursts comprising a first training sequence and the second type bursts comprising a second training sequence, Data of the received data bursts are auto-correlated; and the type of a received data burst is recognized on the basis of a phase value of the auto-correlation result of the training sequence of the data burst.

Abstract: A time slot which is formed by time-division multiplexing is divided into a plurality of blocks in at least a frequency direction, and also within each one of said plurality of blocks a plurality of subcarriers are formed. A predetermined number of plurality of blocks forms one communication channel, whereby a plurality of communications are formed within a time slot. With this, one time slot can be multiplexed by communication of multiple carriers separated in frequency. In this manner, with simple constitution, communication can be performed satisfactorily even in an environment where a multiple path is present.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention relates to a header structure for a TDD system which uses preferably an OFDM transmission system. Thereby a header slot according to the present invention fits entirely into one time slot of the GSM TDD structure. The header slot HS comprises a downlink channel DC and an uplink channel UC. The downlink channel DC comprises a synchronization channel SYNCH, a general broadcast channel GBCCH as well as an optional broadcast channel OBCCH. The uplink channel comprises a random access channel RACH. Both the synchronization channel SYNCH and the general broadcast channel GBCCH can comprise two identical repeated symbols S1, S2. The repetition of the identical symbols S1, S2 provides for a very efficient (secure) data transmission and a high-efficient correlation in view of a frequency and time synchronization due to the large number of samples in the symbols of the synchronization channel SYNCH and the general broadcast channel GBCCH.

Abstract: The present invention relates to a wireless transmission method and a wireless transmission system using an OFDM system comprising a plurality of equally spaced subcarriers. According to the present invention a data and pilot mapping in an OFDM system is proposed. One timeslot thereby comprises two symbols S1, S2, which are OFDM-modulated and have the same time duration. Besides a short guard time and roll-off times, a midamble MA is introduced between the respectively two OFDM-modulated symbols. The time duration of the midamble thereby corresponds to 1/n of the time duration of the symbols S1, S2, n being an integer greater than 1. In case the midamble is also OFDM-modulated, only every n-th subcarrier of the OFDM system is modulated when transmitting the midamble MA. Alternatively the midamble can be transmitted using a single carrier modulation scheme. The midamble MA can be used to transmit pilot symbols for a channel estimation such as to provide a coherent detection.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent sub-carriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.