step

System object: comm.OSTBCCombiner
Package: comm

Combine inputs using orthogonal space-time block code

Syntax

Y = step(H,X,CEST)


Description

Note

Starting in R2016b, instead of using the step method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

Y = step(H,X,CEST) combines the received data, X, and the channel estimate, CEST, to extract the symbols encoded by an OSTBC. Both X and CEST are complex-valued and of the same data type, which can be double, single, or signed fixed point with power-of-two slope and zero bias. When the step method input X has double or single precision, the output, Y, has the same data type as the input. The input channel estimate can remain constant or can vary during each codeword block transmission. The combining algorithm uses the estimate only for the first symbol period per codeword block.

The time domain length, T/SymbolRate, must be a multiple of the codeword block length. T is the output symbol sequence length in the time domain. Specifically, when you set the NumTransmitAntennas property to 2, T/SymbolRate must be a multiple of two. When you set the NumTransmitAntennas property greater than 2, T/SymbolRate must be a multiple of four. For an input of T/SymbolRate rows by NumReceiveAntennas columns, the input channel estimate, CEST, must be a matrix of size T/SymbolRateby NumTransmitAntennas by NumReceiveAntennas. In this case, the extracted symbol data, Y, is a column vector with T elements. Input matrix size can be F by T/SymbolRate by NumReceiveAntennas, where F is an optional dimension (typically frequency domain) over which the combining calculation is independent. In this case, the input channel estimate, CEST, must be a matrix of size F by T/SymbolRate by NumTransmitAntennas by NumReceiveAntennas. The extracted symbol data, Y, is an F rows by T columns matrix.

Note

obj specifies the System object on which to run this step method.

The object performs an initialization the first time the step method is executed. This initialization locks nontunable properties and input specifications. For more information on changing property values, see System Design in MATLAB Using System Objects.