Abstract: A circuit of a node in a radio network and method for transit time measurement between a first node and a second node of a radio network is provided. A frame is transmitted by the first node, wherein the frame requires an acknowledgment of reception by the second node. A first point in time of the transmission of the frame is established by the first node by a time counter. The frame is received by the second node at a second point in time. The acknowledgment is transmitted by the second node to the first node at a third point in time, wherein the third point in time depends on the second point in time by a predetermined time interval between the second point in time and the third point in time. A fourth point in time is established by the first node by the time counter when the acknowledgment is received.

Abstract: A method for a rate increase and a method for a rate reduction of a sampling input sequence into a sampling output sequence is provided. The sampling input sequence is subjected to signal processing. Signal processing maps a spreading with a first factor and an interpolation and a decimation with a second factor to generate the sampling output sequence with use of a counter. The counter and the signal processing are clocked with the higher rate, in each case, of the sampling input sequence or the sampling output sequence, respectively.

Abstract: A system and method for distance measurement between two nodes of a radio network is provided. A first unmodulated carrier signal is transmitted by the first node and received by the second node. A second unmodulated carrier signal is transmitted by the second node and received by the first node. A first value and a second value of a first phase are measured by the first node, whereby the first value of the first phase is assigned to a first frequency of the received second carrier signal and the second value the first phase is assigned to a second frequency of the received second carrier signal, whereby the first frequency and the second frequency have a frequency difference.

Abstract: A transmitter-receiver circuit and a method for distance measurement between a first node and a second node of a radio network is provided, wherein a mode of the first node and a mode of the second node are switched from a normal mode for communication in the radio network to a mode for distance measurement, wherein, in the mode for distance measurement for a transit time measurement, a radio signal is transmitted by the first node and received by the second node and a radio signal is transmitted by the second node and received by the first node and a first distance value is determined by measuring the transit time of the radio signals.

Abstract: A circuit, system, and method for range finding between two nodes of a radio network, in particular in conformance with the industry standard IEEE 802.15.4. A mode for finding the range to a second node is initiated by the first node. A command for range finding with the address of the second node is transmitted from the first node to the second node in the mode for range finding. The second node is switched into the range finding mode by the command. A sequence is controlled by the command in the range finding mode. As a result of the control by the command, a first signal is transmitted by the first node in a transmission time window of the sequence and the first signal is received by the second node in an associated reception time window of the sequence, and a first phase value of the first signal is measured.

Abstract: A method for a rate increase and a method for a rate reduction of a sampling input sequence into a sampling output sequence is provided. The sampling input sequence is subjected to signal processing. Signal processing maps a spreading with a first factor and an interpolation and a decimation with a second factor to generate the sampling output sequence with use of a counter. The counter and the signal processing are clocked with the higher rate, in each case, of the sampling input sequence or the sampling output sequence, respectively.

Abstract: A method for determining the occupancy of a transmission channel using a differentially demodulated signal generated at a transmitter-side with the use of PN sequences from a PN sequence set having a first group of first PN sequences and a second group of second PN sequences. The method provides a) at least two subsequences of an initial code sequence, which is assigned to one of the first PN sequences and can be derived from the sequence by logical operations, but is not identical to it, b) the calculation of at least two correlation results by correlating the differentially demodulated signal with each of the at least two subsequences, and c) the evaluation of the correlation results and generation of an output signal to indicate the occupancy of the transmission channel. Also a device for determining the occupancy of a transmission channel.

Abstract: A method for detecting occupation of an adjacent channel by a signal with the aid of a complex-valued bandpass signal having an information channel component and/or an adjacent channel component. In accordance with the invention, a) a real-valued bandpass signal is derived in that the complex-valued bandpass signal is filtered and the real component is produced from the filtered signal, b) the real-valued bandpass signal is transposed into a first baseband signal, c) the first baseband signal is filtered so that spectral components influenced by the information channel component are suppressed, and d) the first filtered signal is evaluated and a binary occupation signal is generated to indicate the occupation of the adjacent channel as a function of the evaluated first filtered signal. The invention further discloses a corresponding device for detecting occupation, as well as a transmitting/receiving device and an integrated circuit having such a device.

Abstract: The invention relates to a method of multiplexing data words in a multicarrier transmit diversity system. The method comprises the step of generating a plurality of data blocks, each data block comprising data words and each data word containing data symbols derived from a data signal, the step of determining for one or more data blocks in dependence on at least one transmission constraint if the data words of said one or more data blocks are to be multiplexed in the time domain or in the frequency domain and the step of multiplexing the data words of the data blocks in accordance with the determination result.

Abstract: A correlation device is provided that includes an adder for adding an input signal sequence and an auxiliary signal sequence to obtain an addition signal sequence, and a delay element for delaying the addition signal sequence to obtain the auxiliary signal sequence, whereby the delay element has a plurality of coefficient outputs for providing addition signal sequence coefficients. The correlation device comprises further a linking element for the coefficient-wise linking of an addition signal sequence coefficient with a linking coefficient to obtain a correlation result.

Abstract: A method and device is provided for the detection of data symbols contained in a received radio signal, whereby each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock and the PN sequences allocated to the data symbols are offset QPSK modulated. The method of the invention for incoherent detection provides for converting the received radio signal into a complex baseband signal sampled in the chip clock, generating a demodulated signal by differential demodulation of the complex baseband signal sampled in the chip clock, providing the derived sequences, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving, i.e., detecting, the values of the data symbols by evaluating the correlation results.

Abstract: An antenna diversity method and a corresponding communication device are disclosed that may be used in wireless LAN receivers. An AGC (Automatic Gain Control) unit controls a gain when processing signals received from antennae. A periodical switching process is performed between at least two antennae. During this periodical switching process, signals from each of the antennae are received alternately. The gain obtained by processing each received signal by means of the AGC unit is monitored and the obtained gain is compared with a predetermined threshold value. When for one of the at least two antennae the gain is below the predetermined threshold value, the periodical switching process is stopped and the antenna used at the time when stopping the periodical switching process is selected. This technique may provide an improved antenna diversity of low complexity, high performance and a short settling time.

Abstract: An improved data communication receiver technique is provided which avoids demodulation errors due to abrupt phase changes. A receiver is provided for processing an incoming digitized signal. The receiver comprises a pre-processing portion, a phase error correction unit and a signal evaluation unit. The pre-processing portion is adapted to process the digitized signal for providing a non-coherent pre-processed signal. The phase error correction unit is adapted to correct a phase error of the non-coherent pre-processed signal and output a coherent signal. The signal evaluation unit is adapted to extract information from the non-coherent pre-processed signal and to output a data signal representing the extracted information. The phase error correction unit and said signal evaluation unit are configured to operate simultaneously for a predetermined time.

Abstract: An improved decision feedback equalization technique is provided that may be used in data communications receivers such as those in WLAN (Wireless Local Area Network) systems. The decision feedback equalizer comprises a feedforward filter that is connected to receive an input data signal and output a filter representation thereof. The feedforward filter has a filter characteristic that depends on filter coefficient data. The decision feedback equalizer further comprises a filter coefficient computation unit for generating the filter coefficient data and outputting the generated data to the feedforward filter. At least one data processing circuit is provided that receives a mode switch signal for switching its operational mode. The data processing circuit is arranged for performing a feedforward filter function in one operational mode and a filter coefficient computation function in another operational mode.

Abstract: A technique for performing a frequency error correction process is provided that may be used in receivers of wireless local area network systems. The technique comprises a three-phase process generating a frequency approximation value based on a frequency error estimate, starting a channel estimation process that uses the generated frequency approximation value, refining the generated frequency approximation value, and compensating a frequency error using the refined frequency approximation value. Further, a corresponding integrated circuit chip and an operation method are provided. Using the technique for performing a frequency error correction process may provide high reliability, high precision and improved operation speed.

Abstract: A method for detecting occupation of an adjacent channel by a signal with the aid of a complex-valued bandpass signal having an information channel component and/or an adjacent channel component. In accordance with the invention, a) a real-valued bandpass signal is derived in that the complex-valued bandpass signal is filtered and the real component is produced from the filtered signal, b) the real-valued bandpass signal is transposed into a first baseband signal, c) the first baseband signal is filtered so that spectral components influenced by the information channel component are suppressed, and d) the first filtered signal is evaluated and a binary occupation signal is generated to indicate the occupation of the adjacent channel as a function of the evaluated first filtered signal. The invention further discloses a corresponding device for detecting occupation, as well as a transmitting/receiving device and an integrated circuit having such a device.

Abstract: A complementary code decoder technique is provided where the encoded input data is first parallelized. From the parallelized data, correlation values are generated by a correlator circuit that is capable of changing its correlation characteristics depending on at least one control signal. Different control signals are sequentially provided to the correlator circuit thereby driving the correlator circuit to sequentially generate multiple correlation values from the parallelized data, based on different correlation characteristics. From the multiple correlation values, the correlation value that represents the optimum correlation is identified. This technique significantly reduces the gate count of the decoder structure, thus saving chip area and manufacturing costs.

Abstract: A phase error corrector circuit and method are disclosed. In one embodiment, a phase error corrector circuit delays a PSK modulated signal and multiplies the delayed PSK modulated signal by the PSK modulated signal in order to generate a forward phase correction signal. The input signal is then mixed with the forward phase correction signal. In another embodiment, a phase error corrector circuit calculates a forward phase offset of a complex PSK modulated signal. The complex PSK modulated signal is phase shifted in a mixer by a phase difference offset in order to generate a phase corrected signal. A backward phase correction means calculates a backward phase offset based on the phase corrected signal. A subtractor subtracts the forward phase offset from the backward phase offset for outputting a difference phase offset to the mixer.

Abstract: A method and a circuit (44) for estimating channel coefficients in a multi carrier transmit diversity system operating in accordance with a block-coding scheme is described. The method comprises determining from a receive signal (Y) for each channel estimated channel coefficients (?) comprising interference components from adjacent channels artificially introduced during the estimation, deriving estimates for interference components and determining interference-compensated estimates (?F+IC) for the channel coefficients on the basis of the estimates for the interference components.

Abstract: A WLAN (Wireless Local Area Network) receiver with a synchronization unit is provided, wherein the synchronization unit comprises a frequency error correction unit configured to perform a frequency error correction process, a phase error correction unit configured to perform a phase error correction process, a filter circuit capable of applying one of at least two different filter transfer functions, wherein a first one of said at least two different filter transfer functions is a frequency error correction filter transfer function for use in said frequency error correction process and a second one of said at least two different filter transfer functions is a phase error correction filter transfer function for use in said phase error correction process, and a controller unit connected to said filter circuit to select one of said at least two different filter transfer functions.