Abstract: In a method for the error-monitored transmission of data via interfaces of a multi-step communication system, the data is transmitted from a transmitter station to a data-receiving station via at least two relay stations which are connected therebetween and receive and further transmit the data parallel to each other. The data is retransmitted if the transmission has been insufficient due to a request from the receiver end and/or due to the lack of a confirmation from the receiver end. In order to increase performance while reducing power consumption of the system, the request or confirmation is generated only by the receiver station and is sent back to the transmitter station. The relay stations consequently do not generate any confirmations or requests.

Abstract: The distance and relative speed of an object remote from an observation point determined using a signal form which includes two signals having a predetermined spacing relative to each other. The two signals are transmitted for a certain time interval during which the frequency of the signals is modulated in a stepwise fashion. Additionally, the signal sections of the two signals are transmitted alternately for each step so that there is a predetermined frequency spacing between the signal sections being emitted consecutively.

Abstract: OFDM symbols are generated using data from one or more users or from one or more data sources represented on a number of sub-carriers. To inhibit multiple-access interference on application of the CDMA principle, the data are transformed in a data-source specific manner and only subsequently allocated to the sub-carriers, independently of the transformation.

Abstract: The invention relates to a method and device for improving, on the receive side, the transmission quality (residual/bit error rate) of a data transmission system, which is based on orthogonal frequency division multiplexing (OFDM) technology and which is negatively influenced by narrow-band harmonic interference signals. The invention takes into account two technical measures. In one technical measure, a received OFDM symbol is processed by means of a cyclic rotation of the OFDM receive symbol and of a subsequent Nyquist windowing in the time domain whereby leading to a reduction of the interference spectrum outside of the sub-carrier bandwidth. In the other technical measure, a channel estimation of the channel transmission function on the sub-carrier level is effected in parallel with the first technical measure, and the signal-to-noise ratio is calculated or estimated by estimating the interference power on the sub-carrier level.

Abstract: In a method for HPRF-radar measurement of the range and Doppler frequency of at least one target, a transmit signal is generated which consists of two pulse sequences that are interleaved on a pulse to pulse basis, and have the same pulse repetition frequency PRF and the same transmit frequency. The pulses of a first one of the two pulse sequences have a linearly increasing phase value with a fixed phase difference &phgr;1n (greater than zero) from pulse to pulse with &phgr;1n≧0, while the pulses of the second pulse sequence have a linear increasing phase value with a fixed phase difference &phgr;2n which differs from &phgr;1n. The two received base band signals of each individual pulse sequence are Fourier transformed, and the amplitude peaks of the resulting two Fourier spectra are determined.

Abstract: The determination of separation (R) and relative speed (v) of at least one object which is distant from an observation point can be achieved by sending electromagnetic signals from the observation point, with a frequency shift over a modulation range (fSweep), in the form of signal segments (A, B) during a measuring interval, with a frequency separation (fShift) from each other which are transmitted alternately, the echo signals from which are detected after reflecting from the object. The phase difference (&Dgr;&phgr;) of the echo signals arising from each signal segment (A, B) is detected. Said determination occurs with short reaction time and high precision whereby the signal segments (A, B) are transmitted with a stepwise shift each time by a frequency step (fIncr) over the modulation range (fSweep) and at least one sampled value for determination of the phase difference (&Dgr;&phgr;) for each signal segment is taken.

Abstract: In a method for HPRF-radar measurement of the range and Doppler frequency of at least one target, a transmit signal is generated which consists of two pulse sequences that are interleaved on a pulse to pulse basis, and have the same pulse repetition frequency PRF and the same transmit frequency. The pulses of a first one of the two pulse sequences have a linearly increasing phase value with a fixed phase difference &phgr;1n (greater than zero) from pulse to pulse with &phgr;1n≧0, while the pulses of the second pulse sequence have a linear increasing phase value with a fixed phase difference &phgr;2n which differs from &phgr;1n. The two received base band signals of each individual pulse sequence are Fourier transformed, and the amplitude peaks of the resulting two Fourier spectra are determined.

Abstract: A method and arrangement for controlling a system of multiple traffic signals for regulating the traffic of vehicles is described. Traffic data is transmitted by wireless transmission to traffic data processing units assigned individually to a locally limited group of traffic signals, and each traffic data processing unit performs an analysis of the local traffic situation for the environment of the locally limited group of traffic signals up to, at the maximum, the neighboring locally limited groups of traffic signals.

Abstract: The invention relates to a distance measuring device. A transmitting part (E) for electromagnetic radiation especially radar radiation, emits measuring pulses (A, B) which are controlled by a pulse generator (1), and a receiving part (8) is switched to a ready-to-receive mode after a certain, adjustable delay (TDELAY, before a next measuring pulse is emitted, for receiving a reflected pulse during a time gate (18). The aim of the invention is to provide a calibration process taking into account all practical defects. To this end, the pulse generator (1) produces pulses with a multiple of the frequency with which the measuring pulses are repeated and a calibrating cycle in which calibrating pulses (&tgr;0 to &tgr;9) are produced with pulses generated by the pulse generator (1), controlled by the transmitting part (5), is carried out at longer intervals in time.

Abstract: The present invention relates to a CW radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles. The present invention further provides that the transmission (s(t)) can be composed of at least four consecutive chirps (A, B, C, D), each having different slopes. The intersection points of all lines in the distance-relative speed diagram from two chirps (A, B) can be calculated from all the ascertained frequency positions K1,n and K2,p. To validate those intersection points, one may observe whether a peak exists in the Fourier spectrum of a third chirp C at a frequency position K3,q, whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram.

Abstract: In a method for operating a radar system, the object is to determine by simple means and at low cost the distance and/or the radial velocity of at least one target object with high resolution. For this purpose, in each measuring phase of the measurement process in the "pulse FMCW radar system", switchover between a transmission mode and a receiving mode is effected a multiple number of times and at short intervals of time. In the transmission mode, all receiving units of the radar system are switched off, while a pulse-shaped (frequency-modulated) transmission signal with time-successive transmission pulses having a specific pulse-on time and a specific carrier frequency is emitted from at least one transmitter unit of the radar system.

Abstract: A vehicle radar emits four groups of single-frequency stepped radar pulses. In group A, the frequency of each pulse is a fixed amount higher than that of the preceding pulse. In group B, the frequency of each pulse is a fixed amount lower than that of the preceding pulse. In group C, the frequency of each pulse is the same as that of the preceding pulse. In group D, the frequency of each pulse depends on a modulo algorithm. The signals reflected from other vehicles may readily be processed with inexpensive equipment to discriminate among such other vehicles, and to determine the distance to, and relative speed of, each such vehicle.

Abstract: In the particular embodiment disclosed in the specification, a CW radar process for measurement of distances and relative speeds between a vehicle and one or more obstructions including transmitting a sequence of constant-frequency radar signal bursts which follow one another without any time interval during four successive measurements. In the first measurement, the radar signal bursts are of sequentially increasing frequency and in the second measurement they are of sequentially decreasing frequency while in the third measurement they have the same frequency and in the fourth measurement the burst frequencies follow a coded pattern. Demodulation of the signals which are reflected by obstructions is carried out by mixing them with the transmitted signals using only one single-channel mixer providing an output signal which is not the signal of a phase curve but of an amplitude curve.

Abstract: The present invention relates to a signal processing method for a radar system. The transmitted signal here includes a polyphase code that is optimized to the desired range/Doppler range and that is repeated periodically over time.

Abstract: With a frequency-agile pulsed doppler radar with high pulse repetition frequency (HPRF) in the unambiguous velocity region, in order to measure the range of a target the complex time signal derived from the echo signals of a coherent processing interval (CPI) is transformed into the frequency domain, the transformed spectrum is multiplied by a bandpass function with a mean frequency coinciding with the doppler frequency of the target, and the product is transformed back into a time signal. The real envelope of this re-transformed time signal displays a definite leading edge and a steady state region, from which the echo travel time can be estimated. Particular advantages may be derived for the pulsed doppler radar set from a plurality of frequency agile transmitter/receivers operated at the same time at different frequencies, and whose frequency switching times are time-staggered.

Abstract: A method of recognizing targets and suppressing spurious signals in radar equipment, in which the surveillance area is divided, in azimuth and range, into a plurality of radar cells. The method comprises comparing the echo signal of each radar cell with a threshold value, producing a sequence of magnitude related amplitude values of echo signals in certain neighboring cells and deriving the threshold value from a value situated in a specific position in said sequence.