Patent · US Expired

Spread spectrum method

US5235615A · kind A · utility

159Cited by
70References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 21, 1992
Grant dateAug 10, 1993
Priority date
Expiry dateJul 21, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04W56/00
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A method for establishing and communicating synchronous, code division multiple access communications between a base station and a plurality of remote units. A plurality of remote-communications signals which have spread-spectrum modulation are transmitted from the plurality of remote units and arrive simultaneously at the base station. The method includes transmitting repetitively from the base station a access signal having spread-spectrum modulation and receiving the access signal at an accessing-remote unit. The accessing-remote unit transmits an echo signal which has spread-spectrum modulation. The echo signal is received at the base station and a time delay is measured between the access signal and the received echo signal. A protocol signal which has spread-spectrum modulation is transmitted to the accessing-remote unit, with the protocol signal communicating a chip codeword and the time delay measured at the base station. The accessing-remote unit adjusts a delay time such that the communications signal transmitted from the accessing-remote unit arrives simultaneously at the base station with communications signals transmitted from the plurality of remote units. The base st…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.