Pilot pattern for observation-scalar MIMO-OFDM

摘要

In an embodiment, a transmitter includes a transmission path configurable to generate first pilot clusters in response to a matrix, each first pilot cluster including a respective first pilot subsymbol in a first cluster position and a respective second pilot subsymbol in a second cluster position such that a vector formed by the first pilot subsymbols is orthogonal to a vector formed by the second pilot subsymbols, the matrix having a dimension related to a number of cluster positions in each of the first pilot clusters. For example, where such a transmitter transmits simultaneous orthogonal-frequency-division-multiplexed (OFDM) signals (e.g., MIMO-OFDM signals) over respective channels that may impart inter-carrier interference (ICI) to the signals due to Doppler spread, the pattern of the pilot symbols that compose the pilot clusters may allow a receiver of these signals to estimate the responses of these channels more accurately than conventional receivers.

主权项

1. An electronic device comprising:
a plurality of transmit paths each comprising:a pilot generator configured to receive pilot information and generate pilot sub-symbols based upon the pilot information, the pilot sub-symbols being in a form of a pilot pattern matrix having a dual orthogonality such that each column of the pilot pattern matrix is orthogonal to each column of a pilot pattern matrix generated by pilot generators in each other transmit path, and each column of the pilot pattern matrix is orthogonal to each other column of the pilot pattern matrix in a given one of the plurality of transmit paths, each mth column of the pilot pattern matrix Ppat(i) for the ith transmit path Ti being constructed according to an equation:Ppat(i)⁡(:,m)=∑p=0N(i)⁢⁢(ΨA(i)⁡(m,p)·f(s(i)⁡(p),ΨB(i)⁡(m,p)))where 0≦m≦Lp−1, Lp is the number of pilot sub-symbols, 0≦i≦NT−1 where NT is the total number of transmit paths, ΨA(i) is an Lp× N(i) matrix associated with the ith transmit path Ti,ΨA(i)(m,p) is the value of the matrix element located in the mth row and pth column of the matrix ΨA(i),S(i)(p) is the pth element of S(i) where S(i) denotes a set or vector corresponding to the ith transmit path Ti, and where f(S(i)(p)) is given by an equation:
f(S(i)(p))=[1e−j2πΔfp(S(i)(p)) e−j2π2Δfp(S(i)(p)) e−j2π3Δfp(S(i)(p)) . . . e−j2π(Np−1)Δfp(S(i)(p))]T where f(S(i)(p),ΨB(i)(m,p)) denotes the column vector generated by circularly shifting the elements of the column vector f(S(i)(p)) downward a number of times equal to the value (m,p), which is the element in the mth row and the pth column of the matrix ΨB(i) that is another Lp× N(i) matrix associated with the ith transmit antenna Ti, where the respective value of each element of ΨB(i) is an integer that is between 0 and Np−1 inclusive, where 0 a pilot-subcarrier-coefficient generator coupled to said pilot generator and configured to generate from each pilot sub-symbol a respective complex frequency-domain coefficient for mapping to a respective pilot subcarrier; a data generator configured to receive data information and generate data sub-symbols; and a data-subcarrier-coefficient generator coupled to said data generator and configured to generate, from each data symbol, a respective complex frequency domain coefficient for mapping to a respective data subcarrier.