Method and system for estimating a channel frequency response of a training symbol in a block transmission system

1 . A method for estimating a channel frequency response at an ‘i’th pilot sub-carrier of a training symbol in a block transmission system, the channel frequency response being estimated by a receiver, the block transmission system being a frequency reuse system, the method comprising:

a. generating a matrix of pilot codes, the number of rows of the matrix being approximately equal to a block size (L+1), L representing the number of adjacent pilot sub-carriers, each adjacent pilot sub-carrier having a channel frequency response approximately equal to the channel frequency response of the ‘i’th pilot sub-carrier, a column of the matrix comprising the pilot codes corresponding to the adjacent pilot sub-carriers and the ‘i’th pilot sub-carrier of a signal, the number of columns of the matrix being equal to number of signals received by the receiver, the receiver receiving a desired signal and at least one undesired signal;

b. determining whether the matrix is invertible; and

c. calculating the channel frequency response at the ‘i’th pilot sub-carrier corresponding to the desired signal in response to determining whether the matrix is invertible.

2 . The method of claim 1 , wherein calculating comprises:

a. inverting the matrix when the matrix is invertible; and

b. multiplying the inverted matrix and a column matrix, the column matrix comprising values measured at the receiver corresponding to the adjacent pilot sub-carriers and the ‘i’th pilot sub-carrier.

3 . The method of claim 1 , wherein calculation comprises interpolating the channel frequency response of adjacent pilot sub-carriers when the matrix is singular.

4 . The method of claim 3 , wherein the interpolating is performed using a spline interpolation algorithm.

5 . The method of claim 3 , wherein the interpolating is performed using a linear interpolation algorithm.

6 . The method of claim 1 , wherein the training symbol is a mid-amble symbol.

7 . The method of claim 1 , wherein the training symbol is a preamble symbol.

8 . A method for estimating a channel frequency response corresponding to each signal at an ‘i’th pilot sub-carrier of a training symbol in a block transmission system, the channel frequency response estimated by a receiver, the block transmission system being a frequency reuse system, the method comprising:

a. generating a matrix of pilot codes, the number of rows of the matrix approximately equal to a block size (L+1), L representing a number of adjacent pilot sub-carriers, each adjacent pilot sub-carrier having a channel frequency response approximately equal to the channel frequency response of the ‘i’th pilot sub-carrier, a column of the matrix comprising the pilot codes corresponding to the adjacent pilot sub-carriers and the ‘i’th pilot sub-carrier of a signal, the number of columns of the matrix approximately equal to number of signals received by the receiver, the receiver receiving a desired signal and at least one undesired signal;

b. determining whether the matrix is invertible; and

c. calculating the channel frequency response corresponding to each signal at the ‘i’th pilot sub-carrier in response to determining whether the matrix is invertible.

9 . A receiver comprising a channel frequency response estimator, the channel frequency response estimator configured to estimate a channel frequency response corresponding to each signal at an ‘i’th pilot sub-carrier of a training symbol in a block transmission system, wherein the block transmission system includes a frequency reuse system, wherein the channel frequency response estimator comprises:

a. a matrix generator configured to generate a matrix of pilot codes, the number of rows of the matrix approximately equal to a block size (L+1), L representing the number of adjacent pilot sub-carriers, each adjacent pilot sub-carrier having a channel frequency response approximately equal to the channel frequency response of the ‘i’th pilot sub-carrier, a column of the matrix comprising the pilot codes corresponding to the adjacent pilot sub-carriers and the ‘i’th pilot sub-carrier of a signal, the number of columns of the matrix approximately equal to number of signals received by the receiver, the receiver configured to receive a desired signal and at least one undesired signal;

b. a determining module configured to determine whether the matrix is invertible; and

c. a calculator configured to calculate the channel frequency response corresponding to each signal at the ‘i’th pilot sub-carrier in response to determining whether the matrix is invertible.

10 . The receiver of claim 9 , wherein the calculator comprises:

a. a matrix inverter configured to invert the matrix when the matrix is invertible;

and

b. a multiplier configured to multiply the inverted matrix and a column matrix, the column matrix comprising values measured at the receiver corresponding to the adjacent pilot sub-carriers and the ‘i’th pilot sub-carrier.

11 . The receiver of claim 9 , wherein the calculator comprises an interpolator configured to interpolate the channel frequency response of adjacent pilot sub-carriers when the matrix is singular.

12 . The receiver of claim 10 , wherein the calculator further comprises an interpolator configured to interpolate the channel frequency response of adjacent pilot sub-carriers when the matrix is singular.

13 . The receiver of claim 12 , wherein the interpolator is configured to perform spline interpolation.

14 . The receiver of claim 12 , wherein the interpolator is configured to perform linear interpolation.

15 . The receiver of claim 9 , wherein the receiver is configured to receive uplink signals.

16 . The receiver of claim 9 , wherein the receiver is configured to receive downlink signals.

17 . The receiver of claim 16 , wherein the training symbol is a mid-amble symbol.

18 . The receiver of claim 16 , wherein the training symbol is a preamble symbol.

19 . The receiver of claim 9 , wherein the block transmission system includes a frequency reuse-1 system.