Abstract:
PROBLEM TO BE SOLVED: To provide a modem for a transmission system for enabling a single modem to effectively utilize a number of DSL standards with low complexity. SOLUTION: A digital subscriber line transmission using QAM modulation on several equally spaced discrete tones, uses, at a high transmission rate, N=2048/p or 4096/p tones spaced by 4.3125p kHz, where (p) is a power of 2. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To suppress accidental interference without loss of usable band width and without reduction of natural resource further, in wireless communication system. SOLUTION: A wireless apparatus (WAP1), which belongs to the wireless communication system and is constituted so as to exchange information between another wireless apparatus in the system in main frequency band, is provided with N (N is larger than 1) sets of different antennas (ANT1, ANT2) having different antenna characteristics respectively, a controllable selecting means (SWM) constituted so as to select one set of antenna, a detecting means (DTM) constituted so as to detect the accidental existence of at least one interferences operated in the main frequency band by the selected antenna and a control means (CTLM) constituted so as to control the selecting means to select another antenna upon existence of detected interference. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To reduce a quantization noise in a frequency band positioned outside a band used for a signal. SOLUTION: The power amplification device is provided with an input part for receiving a signal having a useful frequency band, and a power amplification means of the delta-sigma type. The power amplification means of the delta-sigma type (MAP) exhibits an order greater than or equal to one in the useful band of the signal and an order greater than or equal to one outside the said useful band. Thus, a position of a zero point of a noise transmission function can be adjusted to adjust an S/N in the useful band, and a value of one or multiple frequency bands positioned outside the useful band of which the quantization noise is desired to be minimized, is made adjustable. COPYRIGHT: (C)2004,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a method for controlling the transmission of a super-wideband position modulation pulse signal with high precision. SOLUTION: In this method, a pulse signal is constituted so as to be involved in a time window. A control signal which contains an identification showing the position of a pulse in a corresponding window, in connection with each pulse is provided for a pulse generator. Further, continuous groups of N bits which coordinately define a digital sign showing the position of a pulse inside the window are transmitted by transmission frequency (Fe) which is greater than a pulse repetition frequency, regarding the respective time windows. The digital position sign is converted to the control signal which is spread in time along the length of the window and contains the position identification, at a moment corresponding to the digital position sign. As a result, the pulse can be positioned inside the window with a time precision equal to 1/N.Fe. COPYRIGHT: (C)2004,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a method for detecting the eventual presence of an interferer, for example, a radar signal, adapted to interfere with a wireless device, for example, an UWB device; and a corresponding device. SOLUTION: In this method for detecting the eventual presence of an interferer adapted to interfere with a wireless device, the wireless device includes at least one receiving chain including an analog to digital conversion (ADC) stage. The method includes: receiving 30, on the receiving chain, an incident signal; delivering 31, to the ADC stage, an analog signal from the incident signal; elaborating 33 a binary information from a binary signal BS delivered by the ADC stage and representative of the level of the analog signal; analyzing 34 a temporal evolution of the binary information BINF; and detecting 35 the eventual presence of the interferer from the analysis. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To integrate a pulse generating function in a command itself so as to control both pulse positions and waveforms and to provide a pulse generationg device which is embodied by CMOS technology in a particularly simple manner. SOLUTION: Successive groups of N bits are delivered at a delivery frequency Fe greater than a predetermined frequency PRF. Each of the groups includes a sub-group composed of at least one bit. The sub-group determines a digital cue of position and of shape of a base pulse within a window of length 1/PRF. The digital queue is converted into the base pulse (MCV), and the base pulse is filtered (FLT) by at least a high-pass filter for delivering a pulse of the ultra wideband type positioned within the window of which temporal accuracy is equal to 1/N.Fe. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To eliminate a write access conflict without increasing entire latency in a CDMA system. SOLUTION: The system is provided with a source memory means divided into N basic source memories, a processing means for producing N data per cycle, a target memory, N interleaving tables, and N cells connected in a ring structure. Each cell is connected among an output of the processing means, one interleaving table and a port of one target memory, each cell receives data from the processing means and two adjacent cells and sends at least several received data to at least one of the adjacent cells or successively writes some of the received data to the related target memory according to contents of the interleaving table. COPYRIGHT: (C)2004,JPO
Abstract:
One problem, frequently encountered with VDSL transmission systems, is that upstream FEXT produced by system users having short wires can be very strong. Users having shorter wires get high bit rates whereas users having longer wires get low bit rates. In extreme cases it may happen that users with wire lengths greater than 1000 meter cannot transmit data upstream. The present invention provides a VDST transmission system with a plurality of modems. The modems are located at varying distances from a central station. There is a target bit rate for each modem. That modems on shorter wires have control means for reducing their transmit power. This reduces the FEXT produced by these modems enabling modems on longer wires to transmit at higher bit rates.