FilterGroup delay impact on binary-offset-carrier modulation

Binary offset carrier (BOC) modulation is equivalent to taking a standard modulation (BPSK, BFSK, ...) and apply a second FSK-like modualtion. Now i was wondering about the impact of the group delay introduced by the front-end filters on the receiver's performances? Indeed if the two lobes of the BOC signal experiment different delays, the perfromance must be degraded. Any thought, articel, reference on this subject?

Regards
Ghost