Abstract: The present invention relates to the field of contention in a network of communicating nodes. The present invention especially relates to a master node for a communication network, to a slave node device for a communication network, to a network comprising the master node device and at least one slave node device and to a method of contention in a network of nodes. The method of contention according to the present invention is method in a network comprising slave nodes, said slave nodes comprising a group of first slave nodes, the method comprising the step of sending, by every first slave node participating in a contention, a number of two or more contention participation messages during a contention window associated with the first slave node.

Abstract: A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other.

Abstract: A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other.

Abstract: A method for establishing a wireless communication link between a first communication device having a beam antenna to be steered to different positions and a second communication device. The method includes transmitting a link request signal from the first communication device to the second communication device via the beam antenna. The link request signal includes information relating to a current position of the beam antenna. The method further includes obtaining, in case the link request signal is received in the second communication device, channel quality information representative of a current transmission path.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively.

Abstract: A method for establishing a wireless communication link between a first communication device having a beam antenna to be steered to different positions and a second communication device. The method includes transmitting a link request signal from the first communication device to the second communication device via the beam antenna. The link request signal includes information relating to a current position of the beam antenna. The method further includes obtaining, in case the link request signal is received in the second communication device, channel quality information representative of a current transmission path.

Abstract: The present invention relates to a receiving apparatus 1 for receiving signals in a communication system, in which the signals are transmitted on the basis of frames, each frame comprising a data part comprising data blocks, wherein the data blocks are respectively separated by a guard sequence, said receiving apparatus 1 comprising correlation means 14 adapted to perform a correlation on the guard sequences of a received signal, clock drift estimation means 15 adapted to perform a clock drift estimation in the frequency domain on the basis of the correlation results from the correlation means 14, and clock drift compensation means 16 adapted to compensate the clock drift of the received signal on the basis of the clock drift estimation. The present invention further relates to a corresponding receiving method.

Abstract: The present invention relates to a synchronization structure for a receiving apparatus for receiving signals in a communication system, in which the signals are transmitted in frames, each frame comprising a synchronization part with synchronization sequences, wherein at least one of the synchronization sequences as a different phase than the other synchronization sequences, comprising correlation means adapted to perform a correlation on the synchronization part, peak detection means adapted to detect candidate correlation peaks and the correlation result, and correlation peak detection means adapted to detect a correlation peak among said candidate correlation peaks on the basis of a confidence value and phase information. The present invention is further related to a corresponding synchronization method. The present invention enable a frame synchronization with a higher performance specifically in low signal to noise ratio environments.

Abstract: A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.

Abstract: The present invention relates to a receiving apparatus for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising an analog to digital converter adapted to convert received signals into digital samples with a sampling rate identical to a symbol rate of the received signals, a channel estimation means adapted to perform a channel estimation on the basis of the dedicated channel estimation sequence comprised in a digital samples of the received signals, an evaluation means adapted to evaluate the channel estimation result from the channel estimation means, and a control means adapted to control a phase of the sampling rate of the analog to digital converter on the basis of an evaluation of the channel estimation result. The present invention further relates to a corresponding receiving method.

Abstract: The present invention relates to a receiving apparatus (1) for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising a channel estimation means (6) adapted to perform a channel estimation on a dedicated channel estimation sequence comprised in a received signal, a noise reduction means (8) adapted to reduce noise in the channel estimation result obtained from the channel estimation means by setting complex samples of the channel estimation result which are below a noise threshold to zero, and a frequency domain equalizing means (12) adapted to perform an equalization on the received signal in the frequency domain on the basis of the noise reduced channel estimation result from the noise reduction means (8). The present invention further relates to corresponding method. The present invention enables an improvement of the equalisation performance.

Abstract: A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.

Abstract: The present invention relates to a method for transmitting signals in a wireless communication system, in which signals are transmitted from a first communication device to a second communication device, said signals being transmitted in consecutive frames, each frame having a preamble section including preamble information, at least one of said first and said second communication devices having a narrow beam antenna which is adapted to be steered to different positions, each of said different positions corresponding to one of a number of different transmissions paths from said to said second communication device, including the steps of transmitting and receiving a first preamble section including preamble information enabling the estimation of a channel quality of a current transmission path, while said narrow beam antenna is in a current position corresponding to said current transmission path, steering said narrow beam antenna from said current position to a different position corresponding to a candidate

Abstract: The present invention relates to a receiving apparatus (11) for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising a gain control means (3) adapted to control the gain of a received signal, a channel estimation means (8) adapted to perform a channel estimation on the basis of a dedicated channel estimation sequence comprised in a received signal, a gain error correction means (12) adapted to correct a gain error in the result of said channel estimation caused by said gain control means (3) on the basis of said dedicated channel estimation sequence comprised in the received signal, and an equalizing means (7) adapted to perform an equalization on the received signal on the basis of the gain corrected channel estimation result. The present invention further relates to a corresponding receiving method.

Abstract: A communication system including a first station having at least two first narrow beam antennas and a second station having at least two second narrow beam antennas. The first and second stations establish a first communication path for wireless communication via a pair of first and second narrow beam antennas. When communication via the first communication path is disturbed by obstacles, the first and second stations automatically establish at least one alternative communication path, which is spatially different from the first communication path, for wireless communication using the at least two first narrow beam antennas and the at least two second narrow beam antennas.

Abstract: The present invention relates to a device for receiving signals in a wireless cellular OFDM system, in which data symbols are transmitted in frequency subcarriers and timeslots. The present invention further relates to a method for channel estimation in such a device. According to the present invention, a channel estimation on the basis of received pilot symbols is performed, whereby the channel estimation for data symbols between pilot symbols is performed by means of a filter, said filter being selected from a set of filters on the basis of an interference reference value.

Abstract: A communication system including a first station having at least two first narrow beam antennas and a second station having at least two second narrow beam antennas. The first and second stations establish a first communication path for wireless communication via a pair of first and second narrow beam antennas. When communication via the first communication path is disturbed by obstacles, the first and second stations automatically establish at least one alternative communication path, which is spatially different from the first communication path, for wireless communication using the at least two first narrow beam antennas and the at least two second narrow beam antennas.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna mean, respectively.

Abstract: A frequency-shift-keying demodulator including a phase shifter for shifting the phase of an input signal by a predetermined degree and outputting a shifted signal, a combining unit for combining the input signal and the shifted signal and for outputting a corresponding signal, and a low-pass filter for filtering the signal output by the combining unit and outputting a low-pass filtered signal, the bandwidth of the low-pass filter being matched with the bandwidth of a data signal included in the input signal, such that the combining unit includes at least one adder for adding the input signal and the shifted signal, and outputting an added signal, and at least one square law detector for receiving the added signal output by the adder and outputting a squared signal which is the square of the added signal, wherein the combining unit outputs the squared signal to the low-pass filter.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively.