What is the channel width for direct sequence spread spectrum (DSSS) and how far apart are their center frequencies spaced?

In direct sequence spread spectrum (DSSS) systems, the channel width and the spacing of center frequencies are important parameters that influence the performance and capacity of the communication system. The correct choice indicates that the channel width is 22 MHz, with the center frequencies spaced 5 MHz apart.

DSSS utilizes a spreading code that expands the data signal over a wider bandwidth than the minimum necessary, which helps in minimizing interference and increasing resistance to jamming. A 22 MHz channel width allows for sufficient bandwidth to accommodate the spread spectrum techniques employed, ensuring effective signal transmission with reduced susceptibility to noise.

The center frequency spacing of 5 MHz is also significant because it ensures that adjacent channels can operate without causing significant interference with one another, maintaining the integrity of each signal being transmitted. This spacing effectively supports multiple channels in the same frequency band, allowing for higher capacity and better resource utilization.

In contrast, the other options provide channel widths and center frequency spacings that do not align with the established norms for DSSS systems. Each of them suggests either a channel width or spacing that is uncommon or not practical for effective DSSS communications, failing to meet the accepted technical standards used in the field.