Patent ID: 7830972

Claim:
A method for a transmitter to transmit pilots to a receiver, the method comprising: transmitting first type pilots to the receiver via one or more transmission antennas using time-frequency resources; and transmitting second type pilots to the receiver via the one or more transmission antennas using time-frequency resources upon which data is transmitted, wherein the time-frequency resources are defined by a plurality of sub-carriers in a frequency domain and a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain, and wherein different pairs of sub-carriers and OFDM symbols within the time-frequency resources are used for transmitting the first type pilots via each of the one or more transmission antennas; wherein data is transmitted on the time-frequency resources upon which the second type pilots are transmitted; and wherein data is not transmitted on the pairs of sub-carriers or OFDM symbols within the time-frequency resources upon which the first type pilots are transmitted.