Fixed wireless loop system having baseband combiner predistortion summing table
US5963549A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Dec 10, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/00
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Disclosed is a method for generating I/Q waveforms for transmission over a CDMA radio channel. The method includes steps of (a) summing, for each of a plurality N of channels, the state of I bits to form an Isum value having a sign bit, the state of Q bits to form a Qsum value having a sign bit, and a total number of active channels to form a channel sum value; (b) applying the Isum value and sign bit, the Qsum value and sign bit, and the channel sum value to an input of a multiplexer; and (c) time multiplexing the inputs to generate first and second sets of output bits. The first set of output bits includes a subset of the Isum value bits, a subset of the Qsum value bits, the I sign bit, and the channel sum value bits. The second set of output bits includes the subset of the Isum value bits, the subset of the Qsum value bits, the Q sign bit, and the channel sum value bits. A next step of the method sequentially applies the first and second sets of output bits to a lookup table memory device for sequentially outputting an I value and a Q value for application to a digital to analog converter for generating I/Q waveforms that are predetermined to reduce transmission power and distor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.