how to eliminate interference in the same center frequency
First of all, the CC1101 supports a number of other frequencies, so as a trivial solution, you can switch to using those.

The other thing that you can do at the RF module level is to "shift" your data out of the problematic region. Now, I am assuming that the other module is on 433MHz and it is not a similar module with similar operation. Let's assume that the interfering module is different than the one you are using.
What you could do, is shift to 4-FSK with the highest DEVIATION_M (refer to the datasheet) but use it as 2-FSK. What you would be trying to do is use the two symbols that cause the largest deviation to the centre carrier frequency to avoid your data being contaminated by the interference. Usually, these two symbols would be 00 and 11 (notice these pairs). This is inefficient of course, but it might work as a quick workaround for you.

But what might be happening is that the other RF module is also behaving in the same way. It might also be doing Frequency Shift Keying, in which case, none of the frequencies your RF module might try to hop to is "safe" from noise.

In this case, you have to work with high levels of noise.

The number one way to guard against this kind of interference is with the use of coding.

This can take many forms and have various complexities. One of the simplest "encoding" schemes is a Repetition Code coupled with simple Majority Decoding scheme. You might notice above that your effective B-FSK used the symbols 00 and 11 which, effectively, is a bit like using a repetition code.

One of the issues you might face in this case is that you do not have access to the internals of the RF module. In other words, the only thing you would be doing here is repeat bits $N$ times and at the reception end, receive a frame and decide what bit was sent by assigning the frame to the majority of bits received (either $0$ or $1$). 

Obviously the question now is, where does the frame start and where does it end?

To deal with this, you are now going to have to embed your data stream on some form of protocol that specifies that your actual message starts with something like 0000000000111111111100001111001101 followed by your encoded bits.

The frame start sequence has equal chances of being contaminated with noise as the rest of the data, but the idea is to be looking in to your incoming data stream for a sequence that looks as close as possible to the frame start sequence.

And thus, progressively, we are going closer and closer to convolutional codes where you would be inserting redundant 0s and 1s in a predictable way in your data stream to be able to decode the most likely sequence to have been sent. That is a bit more involved at the decoding side but convolutional codes are more powerful than plain repetition codes.

Hope this helps.