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Wireless system with transmitter having multiple transmit antennas and combining open loop and closed loop transmit diversities

a technology of open loop and transmit diversities, applied in the field of wireless communications systems, can solve the problems of reducing the return of data error rate to be considered versus the complexity, and affecting the efficiency of future transmissions of the transmitter,

Inactive Publication Date: 2011-09-06
TEXAS INSTR INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to non-ideal occurrences in the feedback information, a closed loop system may be inferior to an open loop system in some situations.
For example, as Doppler fading increases, by the time the feedback information is received by the transmitter, the weights included or derived from the feedback information may be relatively outdated and therefore less effective when applied to future transmissions by the transmitter.
While this approach may improve error rates as compared to fewer antennas for the same system, there are diminishing returns in data error rates to be considered versus the complexities of adding more antennas to a system.

Method used

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  • Wireless system with transmitter having multiple transmit antennas and combining open loop and closed loop transmit diversities
  • Wireless system with transmitter having multiple transmit antennas and combining open loop and closed loop transmit diversities
  • Wireless system with transmitter having multiple transmit antennas and combining open loop and closed loop transmit diversities

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Embodiment Construction

[0031]FIGS. 1 and 2 were described above in the Background Of The Invention section of this document and the reader is assumed to be familiar with the details described in that section.

[0032]FIG. 3 illustrates a diagram of a cellular cunitions system 40 by way of a contemporary example in which the preferred embodiments operate. Within system 40 is shown a base station BST, which includes four antennas AT1 through AT4 along which base station BST may transmit (or receive) CDMA or WCDMA signals. In the preferred embodiment, each antenna in the group of antennas AT1 through AT4 is within approximately three to four meters of another antenna in the group. In other embodiments, however, note that the multiple transmit antennas may be much closer to one another; for example, in an environment where base station BST and user station UST are both indoor stations, the distance between the multiple transmit antennas of base station BST may be on the order of inches. Returning to the example ...

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PUM

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Abstract

A wireless communication system (40). The system comprises transmitter circuitry (42) comprising encoder circuitry (44) for receiving a plurality of symbols (Si). The system further comprises a plurality of antennas (AT1-AT4) coupled to the transmitter circuitry and for transmitting signals from the transmitter circuitry to a receiver (UST), wherein the signals are responsive to the plurality of symbols. Further, the encoder circuitry is for applying open loop diversity and closed loop diversity to the plurality of symbols to form the signals.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]More than one reissue application has been filed for the reissue of U.S. Pat. No. 6,594,473. The reissue applications are application Ser. No. 11 / 287,564 and the instant reissue application.[0002]This application claims the benefit, under 35 U.S.C. §119(e)(1), of U.S. Provisional Application No. 60 / 136,413, filed May 28, 1999, and incorporated herein by this reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0003]Not Applicable.BACKGROUND OF THE INVENTION[0004]The present embodiments relate to wireless communications systems and, more particularly, to transmitters with multiple transmit antennas used in such systems.[0005]Wireless communications have become very prevalent in business, personal, and other applications, and as a result the technology for such communications continues to advance in various areas. One such advancement includes the use of spread spectrum communications, including that of code division m...

Claims

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Application Information

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IPC IPC(8): H03C7/02H04B7/02H04B1/02H04B7/06H04B7/26H04J13/00H04L1/06
CPCH04B7/061H04B7/0634H04B7/0669H04B7/0673H04L1/0618
Inventor DABAK, ANAND G.HOSUR, SRINATH
Owner TEXAS INSTR INC