Resources Contact Us Home
Multicode direct sequence spread spectrum

Image Number 14 for United States Patent #RE37802.

In this patent, we present MultiCode Direct Sequence Spread Spectrum (MC-DSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DSSS code. When viewed as DSSS, MC-DSSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of N.sup.2 operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e., interference between the N DSSS codes. In this patent, we introduce new DSSS codes, which we refer to as the "MC" codes. Such codes allow the information in a MC-DSSS signal to be decoded in a sequence of low complexity parallel operations which reduce the ICI. In addition to low complexity decoding and reduced ICI. MC-DSSS using the MC codes has the following advantages: (1) it does not require the stringent synchronization DSSS requires, (2) it does not require the stringent carrier recovery DSSS requires and (3) it is spectrally efficient.

  Recently Added Patents
XDSL system and signal transmission method, sending device, and receiving device of xDSL system
High dynamic range pixel structure
Haworthia plant named `AMSTERDAM`
System and method for providing dynamic navigation through a property to a selected destination
Gas flow indicator
Belt with light
  Randomly Featured Patents
Wireless communication method and system for routing packets via intra-mesh and extra-mesh routes
Polishing systems, methods of polishing substrates, and methods of preparing liquids for semiconductor fabrication processes
CMOS peak detector and AC filter
Buffet or the like
Airtight cap structure
Modified polyethylene terephthalate molding material
Towbar assembly
Cartridge magnetic tape device having magnetic head cleaning mechanism
Semiconductor wafer cleaning method using a semiconductor wafer cleaning device that supports a lower surface of the wafer
Method and device for initiation and ignition of explosive charges through self-destruction of a laser source