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JPL's Wireless Communication Reference WebsiteChapter: Network Concepts and Standards
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A picoterminal transmits a spread-spectrum signal with a chip rate of 64 kchip/s. These spread-spectrum signals occupy the same bandwidth as the original microterminal signal as the chip rate is equal to the bit rate in the original CODE channel. The spreading code length has been chosen equal to 511. This means that the bit rate of a picoterminal is 64000 / 511=125.2 bit/s. Further, in this network, the bit error probability may not exceed 10^-5 for 99% of the time. This requires a signal-to-noise ratio of 9.6 dB.
The 20/30 GHz transponder bandwidth of the Olympus satellite is divided into frequency bands. Of these frequency bands 100 are meant for the transmissions of 64 kbit/s microterminal signals. The idea is now to use the transponder requirements of two of these 64 kbit/s channels to implement an independent picoterminal data communication network within the CODE system.
