Resources Contact Us Home
Multicode direct sequence spread spectrum

Image Number 16 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
Information display
Resist composition and method for producing resist pattern
Shape memory polymers formed by self-crosslinking of copolymers
Heterogeneous language data typing without executable regeneration
Device for data routing in networks
Image quality assessment
Variants of a family 44 xyloglucanase
  Randomly Featured Patents
Apparatus for displaying the interactions between magnetic fields
Electrostatic copying machine
Variable capacity condenser and pointer
BMP-15 compositions
Process for the preparation of alkylene glycols
Converting object structures for search engines
Silicon carbide semiconductor device and method for producing the same
Method for making device for high resolution electron beam fabrication
Selective enablement of descramblers
Stabilized injectable pharmaceutical compositions containing taxoid anti-neoplastic agents