TD-LTE channel spacing Vs TD-SCDMA channel spacing

Dear all,

I have a question about the channel spacing definition. I hope anyone help me to clarify. For the TD-LTE, the channel spacing could be 1.4, 3, 5, 10, 15 or 20MHz. Let us to take a channel spacing is 5MHz as an example.
In the TD-SCDMA, it also has 1.6MHz channel spacing selection. However, I find it has chip rate = 1.28Mcps. Why TD-LTE does not has chip rate value for each different channel spacing? What is the usage of chip rate?

Another question is about the actual bandwidth calculation. For the TD-SCDMA, the channel bandwidth = 1.6MHz and chip rate = 1.28Mcps. Then, the actual bandwidth for calculation should be 1.6M or 1.28M?
For the TD-LTE, the channel bandwidth = 5MHz. I see the 3GPP document. It said that the useful data must be 90% of energy of bandwidth. Then the actual bandwidth which contains data is 5M x 90% ? Am I correct? If it is incorrect, what is the correct answer?

Thanks

wccheng