Abstract: An ADTap status collect, verification device that can be used in CATV addressable taps is featured by: a fed-back signal monitor located at the front of addressable tap and a fed-back signal detector; Said monitor consists of a receiving circuit, a CPU and radio frequency (RF) transmitting circuit. Said receiving circuit and radio frequency (RF) transmitting circuit are electrically connected with the CPU separately; Said detector consists of radio frequency (RF) receiving circuit, CPU and displaying circuit; said radio frequency (RF) receiving circuit and displaying circuit are electrically connected to CPU; Said monitor and detector are linked for communications. Compared with the existing technology, the present invention has the following effects: by way of supervising the cutting-off status of RF switches of the addressable taps capable of payment collection management, full management on payment collection can be realized. It is easy in management at low management costs.

Abstract: An addressable tap capable of detecting number of TV sets online to watch CATV programs consisting of a main block and a cable connecting from the terminal of said main block and the user. Said main block consists of a main central processing unit (CPU) and RF switches that are electrically connected is featured by: Said cable is equipped with a locking device at its user end and this locking device consists of a detection device and a sub-CPU that communicates with said main CPU; said detection device is electrically connected to the sub-CPU; In case said locking device is plugged out, the detection device will detect the information and transmit it to said microprocessor, which will send the information to said main CPU. Said main CPU will instruct the RF switches to shut off CATV signals at the terminal. the present invention has the following effects: CATV operators can collect different fees in accordance with number of TV sets online to watch TV programs and avoid income losses of CATV operators.

Abstract: An addressable tap with illegal channel detection and cutting-off function consisting of a housing and a power supply module, a filter, a control module and RF switches inside said housing, which are electrically connected to said control module, is featured by: It also includes a tuning device, which can isolate random checking signals input at the front end of CATV channels. Said tuning device is electrically connected to said control module. Compared with the existing technology, the current invention has the following effects: high reliability and promptness in cutting off illegal signals; easy replacement of circuit board of the existing traditional non-addressable taps installed for enhancement to realize channel detection and cutting-off function. As this invention addressable tap can substitute the non-addressable taps in CATV network directly without separate wire laying, it is very easy in installation with very low enhancement costs.

Abstract: An adaptor with foldaway plug components comprising a shell (1) and a plug components (2); said shell (1) has a recess (11) at its front end and said plug components (2) is inserted into the recess (11) of said shell (1); there are axle holes (111) and at least three projected/pitted points (112) in a circular line with the axle hole (111) as the center of circle in certain radius in both sidewalls of the recess (11), in which at least one point is conductive; said plug components (2) comprises a plug main body (21) and a plug (22) and said plug main body (21) has rotation axles (211) in both of its sidewalls. In both sidewalls of said plug (21) there are pitted/projected points (212) corresponding to the projected/pitted points (112), and at least one of such points is in integration with or in contact with said plug (22).

Abstract: An image transmission system for a rear projection television includes a main board module and an optical engine module connected to the main board module. When the system actuates, the main board module receives control and image signals to allow a CPU of the main board module commanding a CPU of the optical engine module. The CPU of the optical engine module commands a light valve unit of the optical engine module to generate images that are then projected onto a screen. Because each module is controlled by its corresponding CPU and has a standardized connection port, the modules can be separately debugged and easily connected to external peripherals, thereby reducing the research and development time.

Abstract: An addressable Tap used in cable TV networks consisting of a power supply module, a filter demodulation module, a control module and 8 switches. Said power supply module, filter demodulation module and switches are electrically connected to the control module. Said modules and switches are all installed on a PCB and contained in a housing, which is compatible and about plus minus 30% of the existing traditional installed Tap in size; said control module uses high performance microprocessor, switches are micro RF switches in order to be of the smallest total size. Compared with the existing technology, this invention is convenient in installation with low costs and will not interrupt the transmitted CATV signal. This invention has excellent control effects by high isolation and with interference signal on this RF switch for its direct cutting-off signals to users who owe payments, its continuous rapid switching between on and off or its ability to add interference into the signals.

Abstract: The present invention provides a CDMA RAKE receiver that computes a data detection using Fast Fourier Transform (FFT) matched filters. Signals received are processed in frequency domain by the RAKE receiver. The RAKE receiver includes a pilot signal spreading code matched filter, a data signal spreading code matched filter and a channel matched filter. The pilot signal spreading code matched filter removes a spreading code of the pilot signal. The data signal spreading code matched filter removes a multiple access spreading code of the data signal. A channel matched filter estimates the channel frequency response and combine the received data signal from different paths before a decision is made. For increasing the CDMA system capacity, the RAKE receiver uses a interference cancellation method. A downlink receiver at a mobile station estimates the interference of a pilot signal and subtracts the pilot interference from the received signal before data detection.

Abstract: A synchronization system and method for obtaining frame, carrier, and sampling synchronization of an input OFDM modulated digital signal having a pseudoperiodic second symbol. The system includes an apparatus for obtaining frame synchronization, and the apparatus includes an envelope detector to detect the first symbol of the input signal, and a differentiator connected to the envelope detector to detect the second symbol. The differentiator includes a first filter having a transfer function H(z)=(1+z.sup.-1) and a second filter having a transfer function H.sub.p (z)=(1-z.sup.-n/2 +z.sup.-n -z.sup.-3n/2), where n equals to a number of samples in the input signal. Synchronization of the carrier frequency offset is obtained by first obtaining the fractional carrier frequency offset, and then obtaining the integral carrier frequency offset through a matched filtering process. Sampling frequency synchronization is obtained through the matched filtering process for determining integral carrier frequency offset.

Abstract: A synchronization system for an input signal having a plurality of OFDM symbols, each symbol having at least one guard interval, includes a correlation device for providing a product of the input signal with a complex conjugate of the input signal delayed for a predetermined period, an arithmetic device for obtaining an argument value of the product, and a detection device for detecting a transition in phase values of an output of the arithmetic device, wherein the transition occurring when the phase value in one portion of the symbol duration is substantially smaller than another portion of the symbol duration. The system additionally includes a power estimator for detecting an OFDM symbol frame of the input signal with reference to a predetermined threshold, and a device for estimating fractional carrier frequency offset.

Abstract: A demodulating system for estimating frequency offset and sampling time error by a Fast Fourier Transform operation, which receives a modulated signal sent from a GMSK (Gaussian Low-Pass Filtered Minimum Shift Keying) or a MSK (Minimum Shift Keying) transmitter and demodulates the signal. The demodulating system uses a Fast Fourier Transform converter to obtain frequency offset and sampling time error by applying to it an initial demodulated result generated from a discriminator or a phase differentiator.

Abstract: A one-bit differential detector for a GMSK signal operates independently of an offset frequency. In particular, a decision signal used by a decision circuit to distinguish between logic "0" and logic "1" is always equal to sin[.DELTA..phi.(T)]. The inventive detector has an improved bit error rate performance in comparison to the prior art.

Abstract: In seismic exploration, linear, multiple fold, common depth point sets of seismograms with three dimensional reflection geometry are used to determine the dip and strike of the subsurface reflecting interfaces and the average velocity of the path of the seismic energy to the reflecting interface. The reflections in each set appear with time differences on a hyperbola with trace spacings determined by the source receiver coordinate distance along the lines of exploration. The offset of the apex of this hyperbola is determined from a normal move-out velocity search of the type performed on two dimensional CDP sets. This search identifies the correct stacking velocity and hyperbola offset which are used to determine dip, strike and average velocity.