Abstract:
The invention relates to a clock recovery apparatus being configured to recover clock information from an input signal. The clock recovery apparatus comprises Fourier transforming means (201) being configured to transform the input signal 5 into a frequency domain signal upon the basis of a Fourier transform, correlating means (215) being configured to correlate the frequency domain signal to obtain a correlation value associated with a certain frequency, and clock recovery means (217) being configured to determine whether the certain frequency corresponds to a clock frequency in order to recover the clock information. 10
Abstract:
The present invention relates to a frame structure and method for supporting a relay. According to an embodiment of the present invention, a method for transmitting a preamble from a network supporting a relay includes transmitting a first preamble for establishing synchronization with at least one of a mobile station and a relay station, and transmitting a second preamble including supplemental information for accurately establishing synchronization with at least one of the mobile station and the relay station.
Abstract:
Die Erfindung bezieht sich u. a. auf eine Taktrückgewinnungseinrichtung (10) mit einem digitalen Datensignaleingang (ElO) zum Einspeisen eines digitalen Datensignals (DATA) und einem Taktausgang (TlO) zur Ausgabe eines rückgewonnenen Taktsignals (QO), wobei das digitale Datensignal eine vorgegebene nominale Taktfrequenz (fn) aufweist. Erfindungsgemäß ist vorgesehen, dass die Taktrückgewinnungseinrichtung durch eine digitale Schaltung gebildet ist.
Abstract:
The invention relates to clock recovery in optical communication systems. Optical clock frequencies are recovered from a plurality of optical channels by using a single optical resonator. The optical resonator is matched with the carrier frequencies (V O , A , V O , B ) and the sideband frequencies (V- 1.A’ V 1.A’ V -1. B’ V 1 . B ) of the data signals (S ΙN . A’ S ΙN . B ) sent at different channels. The separation range of the optical resonator (Δv SR ) is selected such that the clock frequency (V 01 ) of at least one data signal (S IN.A ) is substantially equal to the separation range of the optical resonator (Δv SR ) multiplied by an integer greater than or equal to two. The method according to the invention allows the use of different clock frequencies at different optical channels. Furthermore, the method provides considerable freedom to select the spectral positions of the optical channels.
Abstract:
Wireless communications devices, methods of processing a wireless communication signal, wireless communication synchronization methods and a radio frequency identification device communication method are described. In one aspect, a wireless communication device includes an antenna configured to receive electromagnetic energy corresponding to a wireless communication signal outputted using an interrogator and to output electrical energy corresponding to the received electromagnetic energy, communication circuitry coupled with the antenna and configured to sample the electrical energy to process the wireless communication signal, synchronization circuitry coupled with the antenna and the communication circuitry and configured to generate a clock signal to control sampling of the electrical energy using the communication circuitry, wherein the synchronization circuitry is configured to generate a plurality of transitions within the clock signal responsive to a plurality of transitions of the electrical energy during a first data period and wherein the synchronization circuitry is configured to generate a plurality of transitions within the clock signal during a second data period including generating at least one of the transitions independent of transitions of the electrical energy.
Abstract:
A method and telecommunication system for tracking the carrier phase of a received signal (2, 4) includes the addition of a pilot signal (7) to the data component of the signal prior to modulation and transmission (100). The pilot signal (230) is to have a frequency equal to the inverse of twice a data symbol interval with zero crossings positioned at the midpoint of each symbol interval to avoid interference with the data. The received signal (230) is demodulated to produce a complex data signal from which the pilot signal is detected to provide an estimate of the phase error in the complex data signal (230). The elimination of the phase error from the complex data signal is accomplished through a corrective phase shift (240) that is equal and opposite to the estimated phase error.
Abstract:
A radio receiver system (30) comprises a radio receiver (41), a receiver sample clock (60), which is used for sampling a modulated base-band signal; and a timing correction unit (100). The timing correction unit (100) performs, in the frequency domain, a timing drift compensation between a transmitter sample clock (66) and the receiver sample clock (60), In one example context of implementation, the plural modulated radio frequency carriers have been modulated using Orthogonal Frequency Division Multiplexing (OFDM).
Abstract:
Carrier wave frequency is quickly acquired without burdensome MIPs requirements by limiting the spectral analysis of the incoming channel to the expected band edges. The right and left band edges spectral energy is compared and clock frequency correction is made from the results of this comparison. A band pass filter, such as a Goertzel algorithm filter, is employed to quickly and with processing efficiency perform the spectral analysis at the band edges. Once the direction of the frequency error is derived, the correct frequency can be acquired through a feedback loop employing various iterative correction techniques, such as a gearshift approach in which certain predefined frequency corrections are imposed in decreasing steps until the desired carrier frequency has been acquired.
Abstract:
A flexible bit rate clock recovery unit (30) is provided for recovering a clock signal from an input data signal, where the input data signal is transmissible at different bit rates. The flexible bit rate clock recovery unit includes a plurality of fixed rate clock recovery units (32), where each fixed rate clock recovery units is operative at a different rate to extract an intermediary clock signal from the input data signal; a comparator (34) for generating an encoded data signal based on an amplitude characteristic of each of the intermediary clock signals, where the encoded data signal is indicative of the clock signal associated with the input data signal; and a selector (36) for selecting one of the intermediary clock signals based on the encoded data signal, thereby recovering the clock signal from the input data signal.