Apparatus for compensating for phase difference attendant upon time division multiplexing and method thereof

An apparatus for compensating for a phase in a transmitting system which time division multiplexes a plurality of digital signals and converts a result signal into an analog signal, the apparatus comprising:

• a signal generation logic unit group having a plurality of signal generation logic units, where each of the signal generation logic units generates a predetermined digital signal;
• a phase transition filter group comprising a number of phase transition filters equal to the number of the plurality of digital signals, where each of the phase transition filters performs filtering to generate a signal having a phase transited with respect to an input digital signal based on phase information;
• a multiplexing unit for providing the phase information, which is assigned to each of the plurality of digital signals according to time division multiplexing, to the phase transition filter group and time division multiplexing the plurality of digital signals transmitted from the phase transition filter group and outputting a time domain multiplexed signal;
• a controller operable to provide a control signal, comprising arrangement information of the plurality of digital signals and delay information for each of the plurality of digital signals, to the multiplexing unit in order to control the time division multiplexing;
• a digital-to-analog converter for converting the time division multiplexed digital signal output from the multiplexing unit into an analog signal;
• a sampling and holding unit group comprising a number of sampling and holding units equal to the number of the plurality of digital signals, each of the sampling and holding units operable to sample a corresponding signal from the analog signal output from the digital-to-analog converter and hold the sampled signal in response to a sample hold signal which is generated by the multiplexing unit;
• and
• a low-pass filter group comprising a number of low-pass filters equal to the number of sampling and holding units, the low-pass filters low-pass filtering the sampled and held signals output from the sampling and holding units and outputting analog signals having a phase relation which is the same as the phase relation among the plurality of digital signals at a point of generation.

A method for compensating for a phase difference in a system which transmits a plurality of signals according to time division multiplexing, the method comprising:

• generating a selection signal for the time division multiplexing of the plurality of signals;
• generating predetermined phase information for each of the signals to be selected by the selection signal;
• performing phase transition on each of the signals and outputting the result when it is determined that one of the signals needs to be subjected to the phase transition based on the predetermined phase information and outputting each of the signals unchanged when it is determined that the signals do not need to be subjected to the phase transition based on the predetermined phase information;
• and
• time division multiplexing the signal or signals which have been subjected to the phase transition and the signal or signals which have not been subjected to the phase transition and transmitting a time division multiplexed signal.