Abstract: Disclosed relates to a microstrip antenna, particularly, relates to a dual band microstrip antenna including two slots. The microstrip antenna includes a conductor plate having a first hole and a substrate having a microstrip patch where slots of two different sizes are positioned, the substrate being located on a top of the conductor plate.

Abstract: A method for transmitting data using a satellite channel includes: channel-encoding bit data using an e-BCH code; interleaving the encoded data; modulating the interleaved data according to a CPM scheme using four symbols; and transmitting the modulated data to a hub station.

Abstract: A variable length packet data transmission apparatus and method are provided. The variable length packet data transmission apparatus using a variable length packet transmission technique includes a data transmitter generating synchronization information for synchronizing data communication with a data receiving apparatus, including the generated synchronization information in transmission data to be transmitted according to a variable length packet transmission technique, and transmitting the transmission data including the synchronization information to the data receiving apparatus, and a data receiver receiving the transmission data including synchronization information from a data transmission apparatus, reconstructing the synchronization information included in the received transmission data, and performing synchronization with the data transmission apparatus using the reconstructed synchronization information.

Abstract: Provided is a channel data multiplexing apparatus and method for supporting a variable transmission rate. The channel data multiplexing apparatus includes an input memory for receiving multi-channel baseband data in parallel and storing the baseband data at a first clock rate; an output memory for reading the baseband data stored in the input memory at a second clock rate and storing the baseband data; a multiplexing unit for reading the baseband data stored in the output memory in channel sequence at a third clock rate and outputting the baseband data in serial; and a control unit for controlling address processing and clock rates for data read/write (storage) from/in the input and the output memories and the multiplexing unit depending on a transmission mode.

Abstract: Provided is a method and apparatus for measuring demodulating performance of a communication system. The method includes: commanding the mobile station to modulate test pattern data and transmit test pattern data to the central station; commanding the central station to comparing a demodulation result of the data transmitted from the mobile station with the test pattern data; and receiving the comparison result from the central station.

Abstract: Provided is a scalable transmitting/receiving apparatus and method for improving availability of a broadcasting service, which can allow a reception party to select an optimum video according to an attenuation degree of a broadcasting signal by scalably encoding video data and transmitting it by a different transmission scheme for each layer. The scalable transmitting apparatus for improving availability of a broadcasting service includes: a scalable video encoder for scalably encoding video data to generate scalable video elementary streams having logical layers; a multiplexer for multiplexing the multiple scalable video elementary stream, a compressed audio elementary stream, and program specification information to generate a transport stream; and a scalable transmitter for separating the transport stream into multiple TS packet streams according to pre-given priority information, and transmitting the packet streams by a different transmission scheme for each layer.

Abstract: Provided is a decoding apparatus and method based on a variable error correction value. The decoding method includes setting an initial normalized factor and a normalized factor correction value, initially updating a check node based on the initial normalized factor, and updating the check node based on a variable error correction value acquired by adding the initial normalized factor and the normalized factor correction value.

Abstract: An apparatus for independently extracting streams from a hierarchically-modulated signal and performing a soft-decision, and a method thereof are provided. The apparatus includes: a synchronizing unit for receiving a hierarchically-modulated signal configured of an I-channel signal and a Q-channel signal from an external device and performing a synchronizing process on the received signal; a divaricating unit 410 for divaricating the synchronized signal configured of the I-channel signal and the Q-channel signal from the synchronizing unit; a high priority (HP) stream extracting and soft-decision unit for extracting a HP stream from one of the divaricated signals, and performing a soft-decision; a processing unit for processing the other of the divaricated signals to allow constellation points to be distinguished; and a low priority (LP) stream extracting and soft-decision unit for extracting a LP stream from the processed signal from the processing unit and performing a soft-decision.

Abstract: A soft decision demapping method includes defining distance values between a received signal and coordinates of constellation dots, obtaining a difference between a maximum value of distance values when a first bit is 0 and a maximum value of distance values when the first bit is 1, during a soft decision of the first bit of N-bit received signal symbol, acquiring a difference between a maximum value of distance values when a second bit is 0 and a maximum value of distance values when the second bit is 1, during a soft decision of the second bit of the N-bit received signal symbol, and deriving a difference between a maximum value of distance values when an Nth bit is 0 and a maximum value of distance values when the Nth bit is 1, during a soft decision of the Nth bit of the N-bit received signal symbol.

Abstract: Provided is a frequency error estimating method of a communication system. The method includes receiving a frame, and calculating a frequency error from a SOF field of the received frame.

Abstract: A method for generating and processing a hierarchical packetized elementary stream (PES) packet for digital satellite broadcasting based on SVC (Scalable Video Coding) video is disclosed. That is, when SVC video is applied to a digital satellite broadcasting system, a transmitter side can generate a hierarchical PES packet in consideration of a hierarchical structure of SVC video and a receiver side can effectively process a received hierarchical PES packet.

Abstract: A receiver circuit of a satellite digital video broadcast system includes: a multiplication unit outputting a synchronized reception symbol by multiplying a reception symbol by frequency error information as a feedback; a common autocorrelation unit acquiring autocorrelation values for each symbol by multiplying the synchronized reception symbol by an autocorrelation coefficient; a frame synchronization unit detecting a SOF (Start Of Frame), which is a synchronization word indicating start of a frame, from the autocorrelation values for each symbol; a frequency synchronization unit estimating the frequency error information based on the autocorrelation values for each reception symbol and the SOF; and an SNR estimation unit estimating an SNR (Signal to Noise Ratio) based on the autocorrelation values for each symbol and the SOF.

Abstract: An apparatus and method for generating frames for MPE-FEC decoding are disclosed. The apparatus for generating frames for MPE-FEC decoding includes: a packet reception unit configured to receive a packet; a packet attribute inspection unit configured to inspect whether or not the received packet forms a header part of a section; and a frame generation unit configured to generate a frame according to different methods depending on whether or not the packet forms a header part of a section.

Abstract: A decoding method of an MPE-FEC (MultiProtocol Encapsulation-Forward Error Correction) RS (Reed-Solomon) decoder, includes: substituting a value corresponding to an erasure error position with 0 in a reception signal; calculating a syndrome by using the reception signal; calculating an erasure position polynomial by using erasure information; calculating a modified syndrome by using the syndrome and the erasure position polynomial; calculating an erasure error size polynomial by using the modified syndrome; calculating an error position by using the erasure position polynomial; calculating an error size by using a modified Formey's algorithm; and correcting an error through the error position and the error size.

Abstract: A mobile satellite transmission/reception apparatus and a communications route control method using the same are disclosed. The mobile satellite transmission/reception apparatus comprises: a first antenna unit configured to receive a signal along a first communications route; a second antenna unit configured to receive a signal along a second communications route; and a data processor configured to compare cyclic redundancy check (CRC) values with respect to packet streams of signals respectively received by the first and second antenna units, and change communications route to one of the first and second communications routes if packets having the same CRC value are detected.

Abstract: A satellite broadcasting frame signal demodulation method is disclosed. A demodulation method of a demodulator that demodulates a Digital Video Broadcasting-Satellite—Second Generation (DVB-S2) standard satellite broadcasting frame signal includes: performing symbol synchronization; performing frame synchronization after symbol synchronization; recovering a carrier wave after frame synchronization; and decoding mode code (MODCOD) information to obtain frame configuration information after recovering the carrier wave. This method ensures rapid demodulation and reliable demodulated data.

Abstract: An apparatus and method for correcting a frequency offset in a satellite digital video broadcasting system includes a frequency response transformer for receiving a satellite digital video broadcasting signal and acquiring frequency responses divided into positive and negative frequency parts; a rotation/difference value calculation unit for selecting a frequency response inputted from the frequency response transformer and calculating a first value indicating a difference in area without rotation for the selected frequency response, and calculating a second value indicating a difference in area with rotation for the remaining frequency responses; a zero intersection point calculator for dividing an average slope of a straight line formed by the first and second values by the first value, and calculating a zero intersection point of an area difference value on the straight line; and a frequency offset estimator for correcting the zero intersection point to thereby estimate the frequency offset.

Abstract: Satellite communication transmitter and receiver in a DVB-S2 system are provided. The satellite communication transmitter includes a modulator to modulate a satellite communication signal to be transmitted, and a spread spectrum unit to spread the modulated signal and transmit the spread signal. Accordingly, it is possible to reduce interference with a neighboring channel.

Abstract: Disclosed is a phase error estimating an apparatus and a method which provides improved convergence speed and tracking speed even in mobile channel environment by variably applying the step size for phase error estimation according to channel status. The apparatus for estimating a phase error includes: a posterior probability (APP) average calculating unit for calculating an APP average value from a soft decision result of a currently received symbol; a step size determining unit for determining a step size variably according to channel status; and a phase error estimating unit for estimating a phase error of the currently received symbol from a phase error of a previously received symbol and the APP average value by using the variably determined step size.

Abstract: Provided are an apparatus for controlling handover between heterogeneous networks, a method of performing handover between heterogeneous networks in a mobile router, and a mobile router. The method includes determining whether a handover to a network employing a different method from a network to which the mobile router belongs is required based on information prestored in the mobile router, the network to which the mobile router belongs determined by current location information of the mobile router and performing the handover according to the result of the determination. Mobility detection time can be reduced by applying the handover technique between wireless/satellite networks based on link trigger and location to a mobile router moving at high speed. Thus, service interruption can be prevented regardless of movement speed, even in a satellite shadow region such as a station.