Method for two-level variable chip rate spreading and despreading used in CDMA system
AssigneeThe Research Institute of Telecommunications Transmission
InventorsLi Hao, Pingzhi Fan
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Abstract
This invention involves a two-level variable chip rate spreading and despreading method used in CDMA systems. The total spreading gain is the product of the two level spreading factors. Orthogonal sequences, ZCZ sequences and Pseudo-Noise (PN) sequences can be employed as the first- and second-level spreading codes. By employing the two-level spreading method, the interference existing in the systems can be suppressed efficiently and the system performance can be improved significantly.
Claims8
A method for two-level variable chip rate spreading and despreading in CDMA (Code Division Multiple Access) system, wherein at a transmitting side, a transmitter applying a first level spreading to data information with a first level spreading code, the first level spreading gain being the length of the first level spreading code, and applying a second level spreading to the first level spread chip with a second level spreading code, the second level spreading gain being a length of the second spreading code;
- at a receiving side, a receiver despreading the second level spread chip first, its integrating area being the chip width of the first level spread chip, then despreading the first level spreading chip, its integral area being the width of a information bit.
Dependencies are inferred from the claim text.