| 摘要 |
<p>A single, common correlation filter (CF) core is provided in a wireless system using CDMA (code division multiple access). A plurality of channels with different data rates are provided in the wireless system. The channels provided in the wireless system include the access channel, the maintenance channel, and the traffic channel in which information (e.g., pilot or data symbols or both) is transmitted at the tier 1 (which is the basic despreading rate), tier 2 and tier 3 rates. The data rate for transmitting the information is programmable by an external programmable processor, e.g., a digital signal processor (DSP). A user-unique code, such as a PN (pseudo-random noise) code, is applied to the information being transmitted in the channels of the wireless system. Theinformation is modulated and transmitted in any one of the channels at any data rate. The transmitted information is correlated at the basic despreading rate (i.e., the tier 1 rate) in the correlation filter (CF) of the wireless system by time multiplexing delayed versions of the PN code (or orthogonal code, Walsh code) to the correlation filter core. The correlated information is then demultiplexed and demodulated. The demodulated information is summed at the proper integer multiple of the tier 1 rate to achieve the tier 2 and tier 3 rates. One or more signal components are selected (in terms of the received power, signal-to-noise ratio or multipath width) in a window or time period for optimal information recovery. The selecting step can also be implemented according to a preprogrammed time alignment. Furthermore, outputs from the demodulated information can be provided and combined for temporal diversity. Spatial diversity is achieved by providing a plurality of antennas, and a plurality of receivers at a location and providing a single, common correlation filter at each of the plurality of antennas of the receivers in the wireless system.</p> |
