What is the term for the ratio of the chipping code to data bits in a direct sequence spread spectrum (DSSS) signal?

The correct term for the ratio of the chipping code to data bits in a direct sequence spread spectrum (DSSS) signal is known as chipping gain. This term quantitatively describes how much the spreading of the signal improves the quality or robustness of the communication signal against interference.

In DSSS, the original data signal is multiplied by a pseudo-random chipping code sequence, which spreads the signal over a larger bandwidth. The chipping gain reflects the degree to which the spreading process enhances the signal-to-noise ratio. Essentially, a higher chipping gain means that more chips are used for each data bit, which makes the system more resistant to interference and allows for better detection of the original data.

Other terms, like processing gain and bandwidth efficiency, while they relate to spread spectrum and signal processing concepts, do not specifically define the relationship of the chipping code to the data bits. Processing gain refers to the improvement in the signal-to-noise ratio achieved through processing techniques, while bandwidth efficiency looks at how effectively the bandwidth is used for data transmission—neither of these directly addresses the fundamental relationship provided by chipping gain. Thus, chipping gain is the most accurate term to describe the ratio in question.