Please advise me for the accomodation near Maritime Greenwich University.

I am looking for the accommodation for the course which will start on January in Greenwich University. I am a international student.Please advised me which location should I look for accommodation through which the Central London is not much far way and nor Greenwich University. The area must be good security wise and also close to central london and greenwich .Please tell me which area should I look for which must be cost around 50 pounds to 90 pounds.
And my requirement for room is single bedroom