Abstract:
PURPOSE: A signal transmission method in a digital broadcasting system and an apparatus thereof are provided to efficiently signal information about the scrambling of Physical Layer Pipes (PLP). CONSTITUTION: A signal processor generates a signaling signal which includes a security descriptor. The signal processor generates a signaling packet by processing the generated signaling signal. The security descriptor indicates the modulation and channel coding of a physical layer related to a broadcasting data stream and whether data scrambling is performed. A transmission frame generator (13) generates a data slice packet and a transmission frame based on the signaling packet. A transmission signal generator (14) transmits a transmission signal which is generated by processing the transmission frame. [Reference numerals] (111,AA) Input processing unit; (112,BB) Encoding unit; (113,123,CC) Symbol mapping unit; (114) Data slice forming unit; (115) Interleaving unit; (121) Signal generating unit; (122) Encoding unit; (124) Time interleaving unit; (125) Block generating unit; (126) Frequency interleaving unit; (13) Transmission frame generator; (14) Transmission signal generator
Abstract:
PURPOSE: A method for allocating data and a pilot in accordance with physical layer channel bonding is provided to stably compensate for a channel of a guard band. CONSTITUTION: It is determined whether transmission data exceeds one channel capacity(S410). Only a single channel is used when the transmission data does not exceed one channel capacity(S420). The number of channels used for transmission is determined when the transmission data exceeds one channel capacity(S430). Data and pilot signals are allocated to the in-band of the channel and a guard band between the channels based on the determined number of the channels(S440). QEF(Quasi Error Free) is checked through a feedback channel(S450). The number of subcarriers of the data signal increases. The number of the subcarriers of the pilot signal decreases(S460).
Abstract:
PURPOSE: A method and an apparatus for having variable error correction capability are provided to use stuff field of an MPEG-2 transport stream for error correction, thereby providing Reed-Solomon encoder of the various error correction capability without expansion of hardware. CONSTITUTION: A transmission error correction device(400) comprises a packet receiving unit(401), a field confirmation unit(402) and error correction processor(403). The packet receiving unit receives a packet of a TS(Transport Stream) from a broadcasting system. The field confirmation unit confirms stuff field from received packet. Based on the confirmed stuff field, the error correction processor corrects an error of broadcasting contents.
Abstract:
An apparatus for removing the phase jitter in a cable modem and a method thereof are provided to remove the phase jitter in a slicer of a carrier restoring device by using an output value of a low pass filter within an automatic gain control device. A power detector(410) outputs the mean of an inputted signal. An error measurement unit(420) calculates the error value between the mean value received from the power detector and a reference signal. The first loop filter(430) controls the amplitude of the inputted signal based on the calculated error value and then outputs the controlled signal to a low-pass filter(440). The low-pass filter outputs the signal to a gain control amplifier(400).
Abstract:
Disclosed are a method and an apparatus for compensating variable symbol timing in a non-synchronized OFDM system. The present invention includes synchronizing the frame of a received signal, estimating the symbol timing of each symbol of the frame based on the synchronization, compensating a phase difference, due to a symbol timing offset which changes in a cyclic prefix range due to the frequency offset of a sampling clock and thermal noise, in the symbol timing, and performing channel equalization using a preamble based on a phase-rotation-compensated output.