Abstract:
Ein digitales Rundfunksystem enthält einen Sicherheitsbeschreiber, der darstellt, ob Daten verwürfelt werden, unter bezogenen Informationen beim Verarbeiten von Daten entsprechend einem auszustrahlenden Datenstrom in einer Präambel eines Übertragungsrahmens, und sendet den Übertragungsrahmen. Zu diesem Zweck wird beim Erzeugen und Verarbeiten eines Signalisierungssignals, das auf Modulation und Kanalcodierung in einer physikalischen Schicht bezogen ist, ein Signalisierungssignal erzeugt, das einen Sicherheitsbeschreiber enthält, und auf Basis einer Präambel, die das Signalisierungssignal enthält, wird ein Übertragungsrahmen erzeugt und gesendet.
Abstract:
Es wird eine Vorrichtung für eine optische Netzwerkeinheit (ONU-Vorrichtung) in einem Kabelnetzwerk zur Verfügung gestellt. Die ONU-Vorrichtung enthält ein Kabelmodem, das zum Empfangen von Synchronisationsinformation von einer Kopfstelle durch eine optische Leitung konfiguriert ist, und eine Edge-Quadraturamplitudenmodulation (EQAM), die zum Durchführen einer Synchronisation mit einem in der Kopfstelle enthaltenen Kabelmodemabschlusssystem (CMTS) auf der Basis der Synchronisationsinformation und zum Modulieren eines empfangenen Signals zu einem Funkfrequenz-(RF-)Signal für eine Teilnehmervorrichtung konfiguriert ist. Strukturen mit tief in das Netzwerk gehenden Glasfasern und Mikrozellen können auf einfache Weise angewendet werden, indem zugelassen wird, dass die EQAM nicht einer Kopfstelle sondern in der ONU lokalisiert ist.
Abstract:
PURPOSE: An apparatus and method for dynamically allocating a data rate and an adaptive modulation method and apparatus in a cable system using multi-carrier modulation and demodulation are provided to respectively allocate many bits and little bits through a sub channel having a large SNR and the sub channel having a small SNR by using different SNR information. CONSTITUTION: A headend estimates a SNR(Signal-Noise Ratio) of each sub channel signal received through an upstream receiving part(410). The SNR per the sub channel is estimated from the output of a symbol demapper. The headend estimates the SNR per the sub channel. A channel capacity of each sub channel which can be transmitted is calculated based on the SNR of the each estimated sub channel(420). The headend calculates the channel capacity of each sub channel which can be transmitted. The headend assigns the number of bits per the sub channel based on the calculated channel capacity which can be transmitted. The headend transmits an UCD(Upstream Channel Descriptor)_change message to a cable modem(430).
Abstract:
PURPOSE: A data receiving apparatus of a communication system and a method thereof are provided to accurately detect a data packet by using preamble and to accurately perform automatic gain control by using the strength of a receiving signal corresponding to the detected data packet. CONSTITUTION: A detecting unit(330) calculates a power value of a data packet by using preamble of a data packet within a receiving signal. The detecting unit detects the data packet through the calculated power value. A controlling unit(360) calculates a gain compensating value of the detected data packet. The controlling unit performs AGC(Auto Gain Control) of the detected data packet. A compensating unit(310) compensates a DC offset of the receiving signal.
Abstract:
PURPOSE: A method and an apparatus for decoding a Reed-Solomon code are provided to efficiently decode a Reed-Solomon code by controlling the number of a modified Euclidean algorithm block and RAMs(Random Access Memory) according to the length of a code word demanded in a system. CONSTITUTION: A syndrome calculation block(110) calculates a syndrome for a received code word. One or more modified Eculid algorithm block(120) perform modified Euclidean algorithm calculation. An error location block(130) determines the location of errors based on the result of the modified Euclidean algorithm calculation. An error evaluation block(140) determines the value of the errors based on the result of the modified Euclidean algorithm calculation. An error compensation block(160) compensates for the errors based on a received code word and the determined location of errors and the value of the errors. One or more RAMs(Random Access Memory)(170) store the received code word. A control block(100) determines the number of one or more modified Eculid algorithm blocks and the number of one or more RAMs.
Abstract:
PURPOSE: A power control apparatus and a method thereof in uplink stream channel bonding are provided to increase signal to ratio of a cable modem and to efficiently reduce interference of an adjacent channel. CONSTITUTION: A CMTS(Cable Modem Termination System)(2) includes a power measuring unit(21) and a power control unit(22). The power measuring unit measures each power of a cable modem. The power control unit controls power of each cable modem based on power of the measured cable modem.
Abstract:
PURPOSE: A channel allocation method and apparatus thereof are provided to transmit a parameter which is necessary for transmitting data by changing EHDR(Extended Header) values according to the request of a user. CONSTITUTION: A transmission apparatus transmits a message which requests information for an available bandwidth of all bandwidths(S100). A reception apparatus receives available bandwidth information. The transmission apparatus transmits parameters for a first channel through an EHDR field based on the available bandwidth information(S122). The first channel is allocated based on the parameter for the first channel.