Apparatus and method for transmitting/receiving uplink pilot in frequency division multiple access system

A method for transmitting an uplink pilot in a frequency division multiple access system, the method comprising:

• transmitting data symbols in data symbol intervals of one time slot including the data symbol intervals and inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals;
• transmitting pilot symbols through a first set of frequency elements in the first pilot symbol interval;
• and
• transmitting the pilot symbols through a second set of frequency elements in the second pilot symbol interval.

A method for transmitting an uplink pilot in a frequency division multiple access system, the method comprising:

• transmitting data symbols for terminals in data symbol intervals of one time slot including the data symbol intervals and inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals;
• transmitting first pilot symbols for a first terminal among the terminals through a first set of frequency elements in the first pilot symbol interval;
• and
• transmitting second pilot symbols for a second terminal among the terminals through the first set of frequency elements in the second pilot symbol interval.

An apparatus for transmitting an uplink pilot in a frequency division multiple access system, the apparatus comprising:

• a bit-to-constellation mapper for generating data symbols;
• a pilot sequence generator for generating pilot symbols;
• a selector for selecting the data symbols in data symbol intervals of one time slot including the data symbol intervals and inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals, and selecting the pilot symbols in the first and second pilot symbol intervals;
• and
• a mapper for mapping the data symbols to frequency elements given for data transmission in the data symbol interval before transmission, mapping the pilot symbols through a first set of frequency elements in the first pilot symbol interval before transmission, and waiting in the second pilot symbol interval without mapping the pilot symbols.

An apparatus for receiving an uplink pilot in a frequency division multiple access system, the apparatus comprising:

• a divider for receiving a signal of one time slot including data symbol intervals and inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals, distinguishing the received signal for each frequency element, and dividing the received signal into data symbols of the data symbol intervals and pilot symbols of the first and second pilot symbol intervals;
• a channel estimator for performing channel estimation using the pilot symbols;
• an equalizer for channel-compensating the data symbols using channel estimated values from the channel estimator;
• a demodulator for Orthogonal Frequency Division Multiplexing (OFDM)-demodulating the channel-compensated data symbols;
• and
• a constellation-to-bit mapper for converting the demodulated signal into a bit stream;
• wherein the data symbols are mapped to given frequency elements in the data symbol intervals, the pilot symbols are mapped to a first set of frequency elements in the first pilot symbol interval, and the pilot symbols are mapped to a second set of frequency elements in the second pilot symbol interval.

An apparatus for receiving an uplink pilot in a frequency division multiple access system, the apparatus comprising:

• a divider for receiving a signal of one time slot including data symbol intervals and inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals, distinguishing the received signal for each frequency element, and dividing the received signal into data symbols of the data symbol intervals and pilot symbols of the first and second pilot symbol intervals;
• a channel estimator for performing channel estimation using the pilot symbols;
• an equalizer for channel-compensating the data symbols using channel estimated values from the channel estimator;
• a demodulator for Orthogonal Frequency Division Multiplexing (OFDM)-demodulating the channel-compensated data symbols;
• and
• a constellation-to-bit mapper for converting the demodulated signal into a bit stream;
• wherein the data symbols for terminals are mapped to given frequency elements in the data symbol intervals, first pilot symbols for a first terminal among the pilot symbols are mapped to a first set of frequency elements in the first pilot symbol interval, and second pilot symbols for a second terminal among the pilot symbols are mapped to a second set of frequency elements in the second pilot symbol interval.