A Melbourne man who killed a university researcher in a racially motivated gang assault last year has been jailed for 15 years.

John Caratozzolo, 21, of Melton South told his group of friends he wanted to get a mobile phone from an Indian student, because they had better phones.

Victim ... Dr Zhongjun Cao was fatally bashed as he walked home from Victoria University.

They then attacked 41-year-old Dr Zhongjun Cao, who they took to be of Indian descent, although he was actually Chinese.

The court heard Caratozzolo and a group of six others set upon Dr Cao as he walked home from his work at Victoria University, Footscray, last January. Dr Cao fell to the ground before a laughing Caratozzolo kicked him in the head with enough force to damage his own foot.