Wi-LAN's patented Multi-code Direct Sequence Spread Spectrum technology (MC-DSSS) is the world's most spectrally efficient spread spectrum radio technology, and is the technology that makes it possible to multiply the carrying capacity of traditional spread spectrum systems by as much as ten times. Wi-LAN believes that MC-DSSS is the foundation for third generation (3G) mobile radio networks, including cellular phones, and Wi-LAN has recently filed an intellectual property statement with the International Telecommunications Union offering to make MC-DSSS available for licensing on fair, reasonable and non-discriminatory terms.

MC-DSSS is a spectrally efficient spread spectrum modulation technique that assigns up to N DSSS codes to a single user, where N is the number of chips per DSSS code. These N DSSS codes are all orthogonal. In other words, MC-DSSS enables multiple CDMA codes to be assigned to a single user in a CDMA network, thus increasing throughput. Conventional systems with a single user using three codes not only triple the throughput but also triple the cost of having three full transceivers. In MC-DSSS implementation, the information on all codes can be decoded in a single transformation. The implementation of MC-DSSS has the following advantages:

        It does not require the stringent synchronization DSSS requires: conventional DSSS systems required synchronization to within a fraction of a chip whereas MC-DSSS requires synchronization to within two chips;

        It does not require the stringent carrier recovery DSSS requires: conventional DSSS requires the carrier at the receiver to be phase locked to the received signal whereas the MC-DSSS does not require phase locking the carriers. Commercially available crystals have sufficient stability for MC-DSSS; and

        It is spectrally efficient. )

MC-DSS is used in Wi-LAN's advanced wireless Ethernet bridges.

For more information contact: sales@w-lan.com

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