Patent ID: 7272163

Claim:
A method for two-level variable chip rate spreading and despreading in a CDMA (Code Division Multiple Access) system, the method comprising: at a transmitting side, applying first level spreading to data information with a first level spreading code to produce a first level-spread signal, wherein the first level spreading code produces a first spreading factor of a chips per symbol interval of the data information, and applying second level spreading to the first level-spread signal with a second level spreading code to produce a second level-spread signal, wherein the second level spreading code produces a second spreading factor of b chips per each chip interval of the first level spreading code, wherein b is more than 1, such that a total spreading factor for producing the second level-spread signal is equal to a product of the first spreading factor and the second spreading factor; and at a receiving side, first despreading the second level-spread signal, including integrating with a first interval of substantially a chip width of the first level-spread signal, then despreading the first level-spread signal, including integrating with a second interval of substantially a width of an information bit of the data information.