  The dominating waveform in 5G is orthogonal frequency division multiplexing
(OFDM). OFDM will remain a promising waveform candidate for joint communication
and sensing (JCAS) in 6G since OFDM can provide excellent data transmission
capability and accurate sensing information. This paper proposes a novel
OFDM-based diagonal waveform structure and corresponding signal processing
algorithm. This approach allocates the sensing signals along the diagonal of
the time-frequency resource block. Therefore, the sensing signals in a linear
structure span both the frequency and time domains. The range and velocity of
the object can be estimated simultaneously by applying 1D-discrete Fourier
transform (DFT) to the diagonal sensing signals. Compared to the conventional
2D-DFT OFDM radar algorithm, the computational complexity of the proposed
algorithm is low. In addition, the sensing overhead can be substantially
reduced. The performance of the proposed waveform is evaluated using simulation
and analysis of results.
