根据不同的传输需求，正交线性空时弥散码的形式还可以灵活变化。

Orthogonal linear dispersive space time code can also be used as an adaptive one for different application requirement.

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目前，一种普遍的解决方法是将空时码与正交频分复用（OFDM）相结合，但需要假定信道变化缓慢，从而有足够的时间通过发送训练序列来进行信道估计。

Now, a general solution is that combining STC with OFDM, but it is supposed that the channel changes slowly, so there is enough time to transmit the training sequence for channel estimation.

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针对这种情况，本文给出了一种空时网格码的正交设计方法。 这种方法可以用来构造大天线数目的码字，从而避免了繁琐的码字搜索过程。

So we put forward an orthogonal method which can be used to design the STTC with large number of transmit antennas and avoid the complicated search for the code.

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