Yes, by using MOBITEK SMS API version 7, it can send Chinese/unicode character. However, it cannot support reading Chinese characters at the moment.
For more information, refer to http://www.mobitek.com.my/SMS_Gateway/SMS_API_v7/Manual_Full/sendsmsunicode.html
Alternatively, we recommen MOBITEK SMS Engine — Enterprise Edition. It is not part of the SMS Gateway Development Kit. License fee is payable. For more information, please refer to http://www.mobitek.com.my/SMS_Gateway/SMS_Engine/SMS_Engine-Enterprise_Edition_Guide.pdf