Thank you for the request.
There is no specific psychological strategy that a student can use to shut out bullying completely. Bullying is meant to target a person and invade their space, physically and emotionally. Very few, if any, people can shut that type of intrusion out entirely.
When dealing with bullying, a student is made to feel there is something wrong with them. Self esteem suffers and the students life, including academic performance, usually is affected. In order to cope, a student needs support and ways to balance the bullying, with strategies that either stop the bullying or reduce it greatly.
Those who have more authority need to help the student deal with the situation. School personnel including teachers, counselors and principals need to provide assistance to the student. The student themselves need to set boundaries with the bully. For example, staying in a group and not going around alone helps, as does acting brave, walking away and showing the bully the behavior does not affect them. Bullies like to know they are intimidating their victims. It gives them a sense of power. When that power is taken away because the target won't respond, most bullies give up.
I hope this helps,