Suggest FEC technique
I'm not sure what you mean by "50% error correction FEC technique" (but it doesn't sound very good).

A raw BER of 0.1% is not all that high, so there are many techniques that can get the results you want. Look up terms like BCH Code, Reed-Solomon and Turbo Codes. These techniques will correct nearly all of your errors with very little overhead.

For example, Reed-Solomon works by grouping the bits into (usually) 8-bit "symbols". You group the payload symbols into blocks, and add a number of error-correction symbols to each block. For every two FEC symbols you add to each block, you can correct one symbol error in that block. Based on your raw BER and your target BER, along with considerations such as maximum FEC overhead and maximum latency, you pick the block size and the number of FEC symbols per block.