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Wireless direct sequence spread spectrum digital cellular telephone system

  • US 5,570,349 A
  • Filed: 06/07/1994
  • Issued: 10/29/1996
  • Est. Priority Date: 06/07/1994
  • Status: Expired due to Term
First Claim
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1. In a spread spectrum orthogonal code division multiple access (OCDMA) communication system having at least one base station and a plurality of user handsets in which a set of orthogonal Radamacher-Walsh (RW) function are overlaid with a pseudonoise (PN) sequence forming a coded spreading sequence for an information signal, each orthogonal function of said set carries voice data for a single user in said system, a source of selected carrier signals and means to modulate said information signal on said carrier signal to form a transmit signal with said coded spreading sequence on said transmit signal for radio broadcasting between said at least one base station and said user handsets, each said user handset having a time base and means for controlling its power transmission, and wherein the base station transmits a sounding signal, the method of controlling operation of said handsets, the improvement comprising:

  • (1) measuring the time base error of each handset at said base station and transmitting time base correction information from said base station to each handset and controlling the timing of operation of each handset thereby, respectively, and(2) measuring the power of the sounding signal and performing the compensation of the handset transmit power using instantaneous power control of handset to base station link so as to avoid signal interference.

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