摘要:
Channel selection of a received signal is first of all carried out, in the process, by way of an analog channel selection filter. The signal is then converted to a digital discrete-time and discrete-value signal. Finally, the continuous-time and continuous-value signal profile is determined on the basis of a mathematical reconstruction using the zero crossings {ti} and the phase values {φ(ti)=ki·π/2, kiεN0}, with a mathematical reconstruction algorithm using a function system {φ(t−k)}.
摘要翻译:接收信号的信道选择首先在模拟信道选择滤波器的过程中进行。 然后将信号转换为数字离散时间和离散值信号。 最后,连续时间和连续值信号轮廓是基于使用过零点(t 0)的数学重建和相位值{ph i(t i i i) 利用使用函数系统{phi(i)的函数系统的数学重建算法,使用数学重建算法, tk。
摘要:
In order to improve the reliability and the accuracy of a position-finding method such as the GPS method, the quality of a radio link which is used for the position-finding method is determined by estimating a parameter, in particular the Rice factor of the amplitude distribution density, which is characteristic of the ratio of the strength of a signal transmitted via a line-of-sight path, with respect to the strength of the signals transmitted via non-line-of-sight paths.
摘要:
A data transmission system contains at least two stations between which data bursts are exchanged via radio. A frequency hop is provided between the first channel mid-frequency which is used for the transmission and the second channel mid-frequency which is used for the feedback transmission, the height of the frequency hop corresponding to the intermediate frequency. Therefore, the local oscillators must not be tuned to new frequencies between the transmission and the feedback transmission.
摘要:
The present invention is directed to a receiver for a wire-free communication system for reception of a received signal which is modulated using a digital modulation method having a first frequency conversion device for production of a frequency-converted received signal by conversion of the received signal to an intermediate frequency. The receiver further includes a pre-filter for production of a filtered received signal from the frequency-converted received signal such that the received signal is band-limited, and an analogue/digital converter for production of a binary received signal from the filtered received signal by comparison of the filtered received signal with a level threshold. In addition, the receiver includes a phase reconstruction device for production of a phase-reconstructed received signal by reproduction of the phase of the received signal from the time intervals between zero crossings of the binary received signal, and a mapping device for production of a bit sequence by mapping symbols from the phase-reconstructed received signal onto this bit sequence using the digital modulation method.
摘要:
A receiver (1) of a position-finding system comprises a calculation unit (6, 7, 8) for calculation of a statistical value (Λ) on the basis of a received signal, and a detector unit (9) for comparison of the statistical value (Λ) with a threshold value (κ) and for determining whether the received signal is a synchronized location signal, an estimation unit (10) for estimation of the Rice factor (K) of the radio link via which the received signal has been transmitted, and a determination unit for calculation of the threshold value (κ) on the basis of the Rice factor (K).
摘要:
Apparatus for demodulation of a signal which is frequency-modulated with a data symbol sequence {dk}, having a zero crossing detector (1), a generator (2) for production of a sequence {zi}, with zi being calculated from zero crossings ti and ti+1, and having a unit (3) for reconstruction of the data symbol sequence {dk}, which is characterized by a minimum Euclidean distance between the sequence {zi} and an auxiliary sequence, with each sequence element in the auxiliary sequence being formed from convolution of the data symbol sequence {dk} with a sequence {hi,k} relating to the index k, and with the sequences {hi,k} being functions of the times ti and ti+1.
摘要:
In a method for avoiding transients during switching processes in integrated circuits, a module of the integrated circuit is switched from a first operating state to a second operating state, a load change occurring thereby. In this case, it is ensured that the occurring quotient of load change and time duration for the transition from the first operating state to the second operating state does not exceed a predetermined limit value, thereby reducing or avoiding transients associated with such switching.
摘要:
In a method for estimating a sequence of input data symbols of a CPFSK-modulated data signal transmitted via a faulty channel, in the course of an ACS operation for calculating a transition metric value, an estimated value is determined for the replacement symbol occurring during the linear approximation of the CPFSK. That estimated value is considered in calculating the transition metric value.
摘要:
In a method for estimating a frequency offset (fe, Ωe) of a modulated bandpass signal (s) with an assumed carrier frequency (Ω0) in a mobile radio receiver, times (τj) of the zero cross-overs of the bandpass signal are determined in a first step. Using the times (τj) of the zero cross-overs and the assumed carrier frequency (Ω0), the required frequency offset (fe, Ωe) is estimated in a further step by calculating the DC component of an instantaneous frequency which is given by the frequency of the bandpass signal less the assumed carrier frequency.
摘要:
A detector for zero crossings and a counter which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain, and can be compared in a classification device with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification.