Method of generating pilot pattern for adaptive channel estimation in OFDMA systems, method of transmitting/receiving using the pilot pattern and apparatus thereof
Provided is a method of generating a pilot pattern capable of perform adaptive channel estimation, and a method and apparatus of a base station and a method and apparatus of a terminal using the pilot pattern. The pilot pattern selects pilot symbol positions based on distances from pilots of previous orthogonal frequency division multiple access (OFDMA) symbols to a subcarrier position of a current OFDMA symbol in the frequency domain and the time domain, so that a low pilot density is maintained so as to effectively transmit data, and stable channel estimation performance can be obtained even in a bad channel environment. In addition, the minimum burst allocation size is determined according to the channel environment between the base station and the terminal, guaranteeing channel estimation performance suitable for the channel environment, and improving granularity, channel estimation latency, and channel estimation memory size.
1. A transmitting and receiving method for a terminal, comprising:
(a) receiving a signal transmitted according to a pilot pattern in which pilot intervals for channel estimation can be changed, from a base station, wherein the pilot intervals include intervals in at least one of a time domain or a frequency domain;
(b) detecting an up/downlink burst region from the received signal;
(c) estimating a channel for the received signal after channel estimation latency based on information on the detected downlink burst region,
wherein the up/downlink burst region is determined based on a minimum burst allocation size, and
wherein a value of the pilot interval increases as a value of the minimum burst allocation size decreases, and a value of the pilot interval decreases as a value of the minimum burst allocation size increases.
2. The method of claim 1 , wherein (b) comprises detecting the up/downlink burst region from a frame header of the received signal.
3. The method of claim 2 , further comprising:
(d) generating a pilot pattern in which pilot intervals for channel estimation can be changed; and
(e) generating a transmission signal according to the pilot pattern in the uplink burst region determined based on information on the detected uplink burst region.
4. The method of claim 3 , wherein the pilot pattern is generated by determining pilot positions of each OFDMA symbol within a slot which is a section in which the pilot pattern is repeated in time domain and frequency domains, based on distances from pilot positions of previous OFDMA symbols of the slot to each subcarrier of a current OFDMA symbol excluding subcarriers into which the pilots of the previous OFDMA symbols are inserted, in time and frequency directions.
5. A transmitting and receiving apparatus of a terminal, comprising:
a signal receiver receiving a signal transmitted according to a pilot pattern in which pilot intervals for channel estimation can be changed, from a base station, wherein the pilot intervals include intervals in at least one of a time domain or a frequency domain;
a burst region detector detecting an up and down link burst region from the received signal;
a received signal processor estimating a channel for the received signal after channel estimation latency based on information on the detected downlink burst region,
wherein the up/downlink burst region is determined based on a minimum bast allocation size, and
wherein a value of the pilot interval increases as a value of the minimum burst allocation size decreases, and a value of the pilot interval decreases as a value of the minimum burst allocation size increases.
6. The apparatus of claim 5 , wherein the burst region detector detects the up and down link burst region from a frame header of the received signal.
7. The apparatus of claim 6 , further comprising:
a pilot pattern generator generating a pilot pattern in which pilot intervals for channel estimation can be changed; and
a transmission signal generator generating a transmission signal according to the pilot pattern in the uplink burst region determined based on information on the detected uplink burst region.
8. The method of claim 7 , wherein the pilot pattern is generated by determining pilot positions of each OFDMA symbol within a slot which is a section in which a pilot pattern is repeated in time and frequency domains, based on distances from pilot positions of previous OFDMA symbols of the slot to each subcarrier of a current OFDMA symbol excluding subcarriers into which the pilots of the previous OFDMA symbols are inserted, in time and frequency directions.