Abstract: A method and apparatus for estimating a channel in an Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system. A Least-Square (LS) channel estimator receives a training sequence, and performs LS channel estimation on each of a predetermined number of subcarriers independently. A Split Minimum-Mean-Square-Error (S-MMSE) channel estimator separates the predetermined number of subcarriers into a predetermined number of groups, calculates an S-MMSE filter for a subcarrier in each group, and estimates an S-MMSE channel by applying the S-MMSE filter to each of the groups.

Abstract: A OFDM system, a symbol estimation apparatus and an inter-carrier interference cancellation method for estimating a symbol value using the output of a forward error correction decoder. The OFDM system includes a symbol estimation unit, a time varying channel impulse response estimation unit and an interference cancellation unit. The symbol estimation unit performs forward error correction on a received OFDM signal according to a forward error correction code to estimate a symbol value of the received OFDM signal. The time varying channel impulse response estimation unit estimates a time varying channel impulse response in response to the received OFDM signal. The interference cancellation unit cancels intercarrier interference between carriers of the received OFDM signal based on the estimated symbol value output from the symbol estimation unit and the estimated time varying channel impulse response output from the time varying channel impulse response estimation unit.

Abstract: Disclosed is a demodulation circuit for demodulating an IF signal which is input via an antennal and then over-sampled at a sampling rate four times a frequency of a baseband signal, the demodulation circuit including a mixer for converting the IF signal down to a baseband signal using a coefficient corresponding to either sine values or cosine values, a DEMUX for dividing the down-converted baseband signal into a plurality of signals, and a PPF having a plurality of sub-filters for filtering the divided signals input from the DEMUX and a plurality of adders for operating the output signals of the sub-filters. As a result, the demodulation circuit can be realized in a small hardware size and is capable of reducing power consumption.

Abstract: An apparatus and method for synchronizing a TS packet of a ground wave DMB. The method for synchronizing a TS packet of a ground wave DMB includes deinterleaving and decoding a demodulated TS packet; converting the decoded TS packet formed in a unit of bit into a TS packet formed in a unit of byte; detecting a synchronization point of time of the TS packet converted in a unit of byte; deinterleaving and decoding TS packets continued after the synchronization point of time; and sensing in real time whether or not the decoded TS packets in a predetermined range among the TS packets continued after the synchronized point of time are changed in synchronization due to the change of starting position of the TS packets. By sensing in real time whether or not the TS packets that are RS decoded by the external decoder are synchronized, when the TS packets are not synchronized, they are resynchronized and output so that a normal decoding operation can be performed.

Abstract: Disclosed are a method of and a system for controlling frame synchronization for European Digital Audio Broadcast (DAB), the method including the steps of generating a frame synchronization start-signal with respect to an incoming signal which is input when power is supplied, keeping symbol count values with the value “0” after the frame synchronization start-signal is input, transmitting a frame offset value with respect to the incoming signal, and restarting symbol counting for frame synchronization depending on the frame offset value after the frame offset value is input, wherein the frame synchronization unit may preferably transmit the frame offset value after estimating the frame offset value. In accordance with the method and system described herein, it is possible to achieve frame synchronization in short time, thereby reducing a startup time of a DAB receiver and power consumption which is needed for the frame synchronization.

Abstract: For communicating data frames, a respective data frame is transmitted from each of a plurality of transmitter antennas of a transmitter. In addition, a power of any data field that is of a predetermined data type within the respective data frames is boosted to a maximum available power of the transmitter. Thus, total available power of a transmitter is efficiently used for transmitting data fields of the predetermined data type such as channel estimation preambles transmitted with time orthogonality.

Abstract: Disclosed is a deinterleaving device and method for digital broadcast receivers having a downsized deinterleaver memory. The deinterleaving device includes a memory having storage space for performing the deinterleaving in a number of deinterleaving units over the K groups of input data in correspondence with an interleaving unit at a transmitter; an address generator for reading data written in the memory and generating memory addresses for writing input data; read-enable unit and write-enable unit for reading and writing data written at the generated memory addresses; and a controller for controlling the address generator to generate the memory addresses for the input data in correspondence with the deinterleaving units, the controller controlling the read-enable unit and the write-enable unit to read data written at the memory addresses before writing the input data at the memory addresses.