H04J 13/00 - Definition

Definition statement

This subclass covers:

Code division multiplexing techniques which are related to the division of the communications medium according to codes.

Aspects that are covered include types of codes, generation of codes and allocation of codes to channels.

Relationship between large subject matter areas

With regard to spread-spectrum techniques, the borderline between H04J 13/00 and H04B 1/69 should be determined based on whether the features relevant for classification are focused on the code multiplexing aspects or the implementation of the spread-spectrum technique (e.g. details of how the signals are physically transmitted, received and processed).

Documents classified in H04J 13/00 containing aspects of spectral spreading of interest for search, may also be classified in group H04B 1/69.

With regard to systems that use frequency hopping as a means to divide the communication medium, it has been agreed that that frequency hopping is excluded from H04J 13/00 even if it is used within the context of multiple access. Because the concepts dealt with in H04J 13/00 do not have relevance for FH-CDMA even though frequency hopping can be used for CDMA (i.e. FH-CDMA), this subject-matter is exclusively classified in H04B 1/713.

References relevant to classification in this subclass

This subclass does not cover:

Details of the signal processing which are covered by systems that use frequency hopping as a means to divide the communication medium	H04B 1/713
MC-CDMA	H04J 11/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Implementation of the spread-spectrum technique

H04B 1/69

Synonyms and Keywords

In patent documents the following abbreviations are often used:

CDMA	Code Division Multiple Access
MC-CDMA	Multi-carrier Code Division Multiple Access
OVSF	Orthogonal variable spreading factor