31 results about "Carrier shift" patented technology

A carrier including a body and a gravity modulating module disposed at the body is provided. The gravity modulating module includes a weight block, a tilting sensing assembly and a driver. The tilting sensing assembly is adapted for sensing the tilting condition of the body and sending a left turning signal or a right turning signal. The driver is adapted to move the weight block according to the left turning signal or the right turning signal, so that the center of gravity of the carrier shifts to keep balance.

Disclosed herein is a signal processing apparatus including a processing block configured to perform a carrier shift amount detection process for detecting a carrier shift amount constituting a carrier error used for demodulating an orthogonal frequency division multiplexing signal known as the OFDM signal; and a correction block configured to correct the OFDM signal in accordance with the carrier shift amount. The OFDM signal includes a first preamble signal including subcarriers, and a second preamble signal including subcarriers of which the spacing is narrower than the spacing of the subcarriers included in the first preamble signal. The second preamble signal includes pilot signals which are known signals located at intervals of a predetermined number of subcarriers. The processing block detects the carrier shift amount using a correlation of the subcarriers included in one such second preamble signal.

A tuner selects a channel in a designated frequency band. An FFT circuit converts a received signal in the selected channel into a plurality of carrier signals. A carrier shift detection circuit calculates the correlation between the phase information of each carrier signal and reference phase information prepared in advance. If the correlation is larger than a given threshold, it is determined that an OFDM signal is present in the search target channel. A TMCC extraction circuit analyzes the TMCC of the received signal and determines whether or not digital broadcasts of the search target channel can be received.

A refill module for use with a plunger assembly and having a housing (30), a syringe subassembly (70), a carrier (120) and at least one latching element (170). The syringe subassembly is shiftable within the housing from a retracted position to an injecting position at which its injection tip projects beyond the housing end. The carrier has a passageway in which a plunger of a plunger assembly is insertable for advancement of a piston (80) of the syringe subassembly. The syringe subassembly is engagable by the carrier to be moved from its injecting position to a point at which the injection tip is retracted within the housing when the carrier shifts from a first axial position to a second axial position. The at least one latching element is shiftable relative to the carrier from a retracted arrangement to a latching arrangement such that a latch surface of the latching element restricts a size of the passageway to prevent plunger withdrawal. The carrier is liftable within the housing to retract the injection tip into the housing when the at least one plunger is retracted and a latch abutment surface of that plunger engages the latch surface. When the carrier reaches the second axial position, the at least one latching element is shiftable to move the latch surface clear of the latch abutment surface to allow withdrawal of the at least one plunger from the passageway without further lifting of the carrier.

The invention provides a step wave modulation method for grouping sub-modules of a modular multi-level converter, which includes the following steps: dividing the sub-modules in the commutation chain into N sub-module groups; rounding the reference voltages of the sub-module groups to obtain The rounded reference staircase wave voltage Vstair_wave; distribute the trigger pulse to the sub-modules inside the sub-module group; perform voltage equalization between the sub-module groups. In the present invention, the sub-modules are divided into N sub-module groups, and each sub-module group is regarded as a controllable voltage source. Step wave modulation is used in the sub-module groups, and the N sub-module groups use rounding corrections, which can achieve similar wave shift For the purpose of the phase, the appropriate voltage equalization control method is used for voltage stabilization control between the sub-module groups, which simplifies the complexity of the ladder wave modulation, and greatly reduces the requirements for the software and hardware of the modulation algorithm and the voltage equalization control algorithm.

The invention discloses a method for controlling the midpoint voltage of an NPC three-level inverter based on carrier amplitude shift. K×m and 1-K×m, K is the carrier amplitude adjustment coefficient, m is the modulation ratio, the carrier amplitude is adjusted by adjusting the carrier amplitude adjustment coefficient in real time, and the carrier obtained after the amplitude adjustment is compared with the modulated wave Output PWM signal. The adjustment method of K is: when Unp is greater than Udc / 2, then -1≤K<0; if Unp is equal to Udc / 2, then K=0; if Unp is less than Udc / 2, then 0<K≤1; If Unp is greater than Udc / 2, then 0<K≤1, if Unp is equal to Udc / 2, then K=0, if Unp is less than Udc / 2, then -1≤K<0; where, is the power factor angle , Unp is the inverter midpoint voltage, Udc is the DC bus voltage. The present invention achieves the balance of the midpoint potential by keeping the frequency of the modulating wave and the upper and lower carrier waves unchanged, and changing the amplitudes of the upper and lower carrier waves. The method has the advantages of simple calculation and easy implementation.

The invention discloses an actual data packet restoration method based on 802.11ac. The aims of the invention are that incorrect signal state information feedback and identification of a low signal to noise ratio can be realized, CSI estimation errors are corrected, the signal to noise ratio is improved, an AP and all parallel transmission users of the AP are allowed to select a higher transmission rate at last, and the throughput of the network can also be improved. The adopted technical scheme is as follows: 1) the AP monitors CSI estimation containing errors after receiving a wrong data packet, and divides carriers into ''good'' carriers and ''bad'' carriers with an error rate as the standard, and the AP sends a training sequence to a plurality of users by using downlink beam forming to pass through the ''bad'' carriers; 2) based on the received training sequence, the users estimate the CSI again and report information to the AP to pass through the ''good'' carriers; 3) the AP judges factors causing the CSI errors, and then use different restoration mechanisms; and 4) CSI restoration includes CSI restoration of three factors of carrier shift, undersampled estimation and the low signal to noise ratio, and a composite factor of the three factors.

A TMCC carrier is demodulated from a received OFDM signal having a TMCC carrier. A relative carrier position of the demodulated TMCC carrier is detected. A carrier shift amount is detected from the detected relative carrier position of the TMCC carrier and a normal TMCC carrier position. The received OFDM signal is corrected for the carrier frequency shift based on the detected carrier shift amount.

A harmonic generator and a method for detecting grid components through the harmonic generator, the harmonic generator includes a three-phase inverter unit and a calculation control unit, the three-phase inverter unit includes a step-up transformer, a rectifier circuit, an inverter connected in sequence Transformation circuit and sampling circuit, the sampling circuit includes a current sampling circuit and a voltage sampling circuit, the calculation control unit includes a CPU and a display screen connected to it, the sampling circuit is connected to the CPU, and the CPU drives the IGBT in the inverter circuit on and off through the drive circuit The method includes: first input the harmonic size and frequency through the display screen to the CPU to make the command current, and then generate the SPWM signal to the IGBT through the carrier phase shift and current tracking, and the CPU reversely calculates the sampled voltage signal at the same time. The terminal voltage of the product under test can be used to calculate the loss and reactance value of the product under test under the corresponding harmonic.