APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING DATA CHANNEL IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM
A transmission/reception apparatus for transmitting packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system. The apparatus includes a transmission module for generating a frame of an OFDM symbol including pilot tones using the packet data, and transmitting the frame to a wireless network; and a controller for changing at least one of a Pilot-to-Data Ratio (PDR) of the pilot tones and a density of the pilot tones based on a length of the frame. The reception apparatus includes a reception module for receiving a frame of an OFDM symbol including pilot tones from a wireless network, extracting the pilot tone from the received frame, performing channel estimation thereon, and demodulating the packet data; and a controller for receiving at least one of a PDR of the pilot tone and a density of the pilot tone, both of which are in proportion to a length of the frame, and controlling the reception module so that the channel estimation is performed, based on the received information.
1 . A transmission apparatus for transmitting packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system, the apparatus comprising:
a transmission module for generating a frame of an OFDM symbol including pilot tones using the packet data, and transmitting the frame to a wireless network; and
a controller for changing at least one of a Pilot-to-Data Ratio (PDR) of the pilot tones and a density of the pilot tones based on a length of the frame.
2 . The transmission apparatus of claim 1 , wherein the controller comprises a frame length decider for determining a length of the frame based on frame information input from an upper layer.
3 . The transmission apparatus of claim 2 , wherein the controller further comprises a pilot tone PDR generator for adjusting a value of the PDR in proportion to a length of the frame.
4 . The transmission apparatus of claim 3 , wherein the pilot tone PDR generator determines the PDR value using a PDR value corresponding to the frame length received from the upper layer.
5 . The transmission apparatus of claim 3 , wherein the pilot tone PDR generator determines the PDR value using a PDR value corresponding to a frame length previously stored in an internal memory.
6 . The transmission apparatus of claim 2 , wherein the controller further comprises a pilot tone pattern generator for adjusting a pattern of the pilot tones so that a density of the pilot tones is changed in proportion to a length of the frame.
7 . The transmission apparatus of claim 6 , wherein the pilot tone pattern generator determines the density value of the pilot tones using a density value of the pilot tones, corresponding to the frame length received from the upper layer.
8 . The transmission apparatus of claim 6 , wherein the pilot tone pattern generator determines the density value of the pilot tones using a density value of the pilot tones, corresponding to the frame length previously stored in an internal memory.
9 . A transmission method for transmitting packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system, the method comprising:
receiving, from an upper layer, frame information including a length of a frame over which the packet data is transmitted;
changing at least one of a Pilot-to-Data Ratio (PDR) of pilot tones and a density of pilot tones based on the length of the frame; and
generating a frame of an OFDM symbol including the pilot tones using the packet data, and transmitting the frame to a wireless network.
10 . The transmission method of claim 9 , further comprising:
adjusting a pattern of the pilot tones according to the change in the density of the pilot tones.
11 . A reception apparatus for receiving packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system, the apparatus comprising:
a reception module for receiving a frame of an OFDM symbol including pilot tones from a wireless network, extracting the pilot tone from the received frame, performing channel estimation on the extracted pilot tone, and demodulating the packet data; and
a controller for receiving at least one of a Pilot-to-Data Ratio (PDR) of the pilot tone and a density of the pilot tone, both of which are in proportion to a length of the frame, and controlling the reception module so that the channel estimation is performed, based on the received information.
12 . The reception apparatus of claim 11 , wherein the controller further comprises a pilot tone PDR recognizer for determining a value of the PDR in proportion to a length of the frame.
13 . The reception apparatus of claim 12 , wherein the pilot tone PDR recognizer determines the PDR value using a PDR value corresponding to the frame length received from an upper layer.
14 . The reception apparatus of claim 12 , wherein the pilot tone PDR recognizer determines the PDR value using a PDR value corresponding to the frame length previously stored in an internal memory.
15 . The reception apparatus of claim 11 , wherein the controller further comprises a pilot tone pattern recognizer for adjusting a pattern of the pilot tones so that the density of the pilot tones is changed in proportion to the length of the frame.
16 . The reception apparatus of claim 15 , wherein the pilot tone pattern recognizer determines the density value of the pilot tones using a density value of the pilot tones, corresponding to the frame length received from an upper layer.
17 . The reception apparatus of claim 15 , wherein the pilot tone pattern recognizer determines the density value of the pilot tones using a density value of the pilot tones, corresponding to the frame length previously stored in an internal memory.
18 . A reception method for receiving packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system, the method comprising:
receiving, from a control channel, frame information including a length of a frame over which the packet data is transmitted;
receiving at least one of a Pilot-to-Data Ratio (PDR) of pilot tones and a density of pilot tones in proportion to a length of the frame; and
estimating a channel according to the reception result, and receiving the packet data according to the channel estimation.