A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

The invention relates to an apparatus for communicating with a transponder. The apparatus includes a transmit apparatus, a receive apparatus and an evaluation apparatus. The transmit apparatus transmits a transmit signal to the transponder. Based on a signal emitted by the transponder, the receive apparatus receives a receive signal. Based on the transmit signal and/or a signal portion, the evaluation apparatus evaluates the receive signal with respect to data errors. Further, the invention relates to a respective method as well as to a system for communicating.

A synchronized in-phase/quadrature phase (I/Q) detection circuit and a method of the same are provided. The synchronized I/Q detection circuit includes a first logic circuit; a first filter; a first reset and sampling circuit; a first multiplexer; a second logic circuit; a second filter; a second reset and sampling circuit; a signal generator; and a comparator.

Included are a first signal exchanger (13) for exchanging a TXI signal and a TXQ signal output from a transmission baseband unit (2) to signal paths (21) and (22), and a TX control unit (50) for controlling generation of the TXI signal and the TXQ signal in the transmission baseband unit (2) on the basis of a measurement result of a reception baseband unit (5) before and after exchange of the signals by the first signal exchanger (13). As a result, a transceiver only needs to have a single local signal generating unit (1) mounted thereon as a local signal generating unit that is an analog circuit.

An apparatus and a method for synchronizing a Digital Frequency Shift (DFS) for a signal to be transmitted over a wireless channel are disclosed. For example, the method, by a synchronizer, transmits a DFS trigger to a Digital Front End (DFE) processor and a Local Oscillator (LO) trigger to an LO in a synchronous manner, the method, by the DFE processor, applies a DFS on received data in response to receiving the DFS trigger, the method, by the LO, applies a complementary shift on a carrier signal in response to receiving the LO trigger, the method, by the upconverter, digital-to-analog converts and radio frequency modulates the digital frequency-shifted received data and the complementary-shifted carrier signal. In another example, the method, by the synchronizer, transmits a phase error to a phase error corrector that performs a phase error correction.

A carrier recovery system for a receiver of a phase-modulated signal N-PSK, the system including a first pre-conditioning circuit of the signal received (S(t)), with the pre-conditioned signal (SP(t)) having a component, non-modulated in phase, at the frequency N.sub.c where .sub.c is the carrier used for the modulation N-PSK, and a carrier regeneration circuit to regenerate two sinusoidal signals in quadrature at the frequency .sub.c, with these signals being phase locked with respect to said non-modulated component in phase of the pre-conditioned signal.

A digital receiver being adapted for receiving an MSK modulated signal, comprises a digital front-end unit (10) adapted for providing samples having a phase value (.sub.measure) of a down-mixed signal, a phase compensation unit (11) adapted for compensating the phase value (.sub.measure) by delivering a phase offset compensated sample having a phase value (.sub.sync), and a coherent demodulator (12) adapted for recovering information content from the phase offset compensated sample. The phase compensation unit (11) is adapted for analyzing a phase value (.sub.sync) of the phase offset compensated sample, calculating a phase offset value (.sub.offset) based on the phase value (.sub.sync) of the phase offset compensated sample, and applying the phase offset value (.sub.offset) when delivering a subsequent phase offset compensated sample.

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

A measuring device in which a non-electrical variable is converted into an electrical measurement signal via an electrical alternating current having a frequency, wherein the measurement signal contains a signal portion dependent on the non-electrical variable and is double the frequency, and a fault signal portion dependent on the alternating current and is at the frequency, where the measurement signal is pre-processed and digitized to generate a digital signal that is detected and processed to generate a measured value proportional to the non-electrical variable and to generate a fault signal value, wherein the fault signal value is utilized to normalize the measured value that is normalized in a normalizing stage, by forming the quotient using the square of the fault signal value, and is output as a normalized measured value.

A saver sub includes a hollow, tubular body having an upper portion and a lower portion. The upper portion is coupled to a kelly or a top drive, and the lower portion is coupled to a drill string. An insulation layer is positioned between the upper portion and the lower portion.