Input 0 is incompatible with layer lstm_15: expected ndim=3, found ndim=4

在keras里用LSTM层分析时间序列是遇到Input 0 is incompatible with layer lstm_15: expected ndim=3, found ndim=4的问题，
我的输入shape是(8064, 1600, 1)，输出是(40,)；lstm层设计如下：

    model = Sequential()
    model.add(LSTM(3, input_shape=(None,1600,1)))
    print(model.layers)

怎么会出现found ndim=4呢？

你好解决了吗