Method and apparatus for pilot signal transmission
AssigneeMotorola Mobility LLC
InventorsTimothy A. Thomas, Kevin L. Baum, Brian K. Classon, Vijay Nangia
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Abstract
A pilot transmission scheme is presented where during a first OFDM symbol period a first pilot sequence is transmitted over a first multiple sub-carriers on a first group of antennas. During a second OFDM symbol period, a second pilot sequence is transmitted over a second multiple sub-carriers on a second group of antennas. The first and the second groups of antennas only transmit one pilot sequence every subframe of M OFDM symbol periods.
Claims19
A method for pilot transmission in an Orthogonal Frequency Division Multiplexed (OFDM) system for a base unit having multiple transmit antennas, the method comprising the steps of:
- transmitting via a transmitter in a communication system, a first pilot sequence at a first time during a first symbol period over a first multiple sub-carriers on a first group of antennas;
- and
- transmitting via the transmitter a second pilot sequence at a second time during a second symbol period over a second same or differing multiple subcarriers on a second group of antennas, wherein the first and the second groups of antennas only transmit one pilot sequence every subframe of M OFDM symbol periods;
- wherein the step of transmitting the first pilot sequence comprises the step of transmitting a same first pilot sequence from each of the antennas in the first group of antennas during the first symbol period;
- wherein the first group of antennas does not transmit on the second multiple subcarriers during the second symbol period when the second group of antennas are transmitting pilot sequences and wherein the second group of antennas does not transmit on the first multiple subcarriers during the first symbol period when the first group of antennas are transmitting pilot sequences;
- and
- wherein the first symbol period is different from the second symbol period and the first pilot sequence is different from the second pilot sequence.
A base unit in an Orthogonal Frequency Division Multiplexed (OFDM) system comprising:
- a first group of antennas that during a first symbol period transmit a same pilot sequence over a first multiple sub-carriers;
- and
- a second group of antennas that during a second symbol period transmit a second pilot sequence over a second same or differing multiple sub-carriers, wherein the first and the second group of antennas only transmit one pilot sequence every subframe of M OFDM symbol periods;
- wherein the first group of antennas does not transmit on the second multiple subcarriers during the second symbol period when the second group of antennas are transmitting pilot sequences and wherein the second group of antennas does not transmit on the first multiple subcarriers during the first symbol period when the first group of antennas are transmitting pilot sequences;
- and
- wherein the first symbol period is different from the second symbol period and the first pilot sequence is different from the second pilot sequence.
A method for pilot reception at a remote unit in an Orthogonal Frequency Division Multiplexed (OFDM) system, the method comprising the steps of:
- receiving by a receiver a first pilot sequence at a first time, during a first symbol period over a first multiple sub-carriers, the first pilot sequence transmitted by all antennas within a first group of antennas;
- and
- receiving by the receiver, a second pilot sequence at a second time, during a second symbol period over a second multiple sub-carriers, the second pilot sequence transmitted on a second group of antennas, wherein the first and the second group of antennas only transmit one pilot sequence every subframe of M OFDM symbol periods, wherein the first group of antennas does not transmit on the second multiple subcarriers during the second symbol period when the second group of antennas are transmitting pilot sequences and wherein the second group of antennas does not transmit on the first multiple subcarriers during the first symbol period when the first group of antennas are transmitting pilot sequences and wherein the first symbol period is different from the second symbol period and the first pilot sequence is different from the second pilot sequence.
Dependencies are inferred from the claim text.