Understanding DPSK Encoding
In a Differential Phase Shift Keying (DPSK) system, the phase of the carrier signal is altered based on the difference between successive bits of the input message. Let's analyze the transmission of the message sequence "110 111 001 010" starting with a reference bit of '1'.

Reference Bit
- The reference bit is '1', which corresponds to a phase of 0 degrees.

Message Sequence Encoding
1. **First Bit '1':**
- Phase remains 0 degrees (reference).
2. **Second Bit '1':**
- No change from the previous bit (0 degrees).
- Phase remains 0 degrees.
3. **Third Bit '0':**
- This indicates a change in phase.
- From 0 degrees to 180 degrees (180 degrees phase shift).
4. **Fourth Bit '1':**
- No change from the previous bit (180 degrees).
- Phase remains 180 degrees.
5. **Fifth Bit '1':**
- No change from the previous bit (180 degrees).
- Phase remains 180 degrees.
6. **Sixth Bit '0':**
- Indicates a change in phase.
- From 180 degrees to 0 degrees (180 degrees phase shift).
7. **Seventh Bit '1':**
- No change from the previous bit (0 degrees).
- Phase remains 0 degrees.
8. **Eighth Bit '0':**
- Indicates a change in phase.
- From 0 degrees to 180 degrees (180 degrees phase shift).

Final Phase Sequence
- The transmitted phases for each bit are:
- **1**: 0 degrees
- **1**: 0 degrees
- **0**: 180 degrees
- **1**: 180 degrees
- **1**: 180 degrees
- **0**: 0 degrees
- **1**: 0 degrees
- **0**: 180 degrees

Conclusion
The transmitted phase carrier for the DPSK system, based on the given sequence starting with a reference bit of '1', will oscillate between 0 degrees and 180 degrees according to the changes in the input bit sequence.