Patent ID: 8400908

Claim:
A method of transmitting a midamble in a wireless communication system, the method comprising: generating a midamble sequence for each of a plurality of antennas; and transmitting the midamble sequence to a user equipment for each antenna, wherein a location of a subcarrier to which each midamble sequence is mapped is determined based on a frequency reuse factor (FRF), wherein the location of the subcarrier to which each midamble sequence is mapped is determined based on the following equation: b k = { 3 · 10 0.2 · { 1 - 2 · G ⁡ ( [ k + u + offset D ⁡ ( fft ) ] ⁢ mod ⁢ ⁢ fft ) } , when ⁢ ⁢ k ≠ N used - 1 2 , ( k - s ) ⁢ mod ⁡ ( 3 · N t ) = 3 · g + ( ⌊ BSID 256 ⌋ + ⌊ k - s N 1 × N sc ⌋ ) ⁢ mod ⁢ ⁢ 3 0 , when ⁢ ⁢ otherwise where b k is a complex coefficient for modulating subcarriers in an orthogonal frequency division multiplexing (OFDM) symbol to which the midamble sequence is mapped, k is a subcarrier index (0≦k≦N used −1), N used is the number of subcarriers to which a midamble sequence is mapped, Nt is the number of transmit antennas, G(x) is a Golay sequence (0≦x<2047) having a length of 2048 bits, fft is a fast Fourier transform (FFT) size, BSID is a cell identifier (ID), u is a shift value (0≦u≦127) which can be determined by u=mod(BSID, 128), offset D (fft) is an offset value which differs depending on an FFT size, g is a transmit antenna index, and s is a parameter that varies depending on k wherein s=0 when k≦(N used −1)/2 and s=1 when k>(N used −1)/2.