Microprocessor controlled iterative switching FM/PM receiver for reconstructing noise-corrupted redundantly transmitted information

• US 4,286,334 A
• Filed: 08/18/1978
• Issued: 08/25/1981
• Est. Priority Date: 08/29/1977
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Gammel, Josef, Fulda, Rainer
• Primary Examiner(s): Safourek, Benedict V.
• Application Number:
  US05/934,950
• Time in Patent Office: 1,103 Days
• Field of Search: 325/42, 325/65, 325/320, 325/41, 325/474, 325/323, 325/324, 325/348, 325/478, 343/18 E, 178/88, 340/146.1 BA, 340/146.1 BE, 371/31, 371/67, 371/68, 371/69, 375/38, 375/40, 375/100, 375/58, 375/51, 375/57, 455/52, 455/59, 455/63
• US Class Current: 375/267
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00

Abstract

A radio communications transmission system in which the communication information is digitalized and impressed on a radio frequency carrier by means of frequency modulation and/or phase modulation and wherein at the receiving station the interference is recognized as amplitude modulation occurring at the output of the intermediate frequency stage and wherein when such interference occurrence is recognized the received data is identified as being faulty and is replaced by redundantly transmitted data which is received and stored at the receiving side so as to provide accurate transmission of data.

Claims

1. The method of transmitting redundant binary coded data information comprising the steps of:

frequency or phase modulating said data on a carrier signal and radiating said signal at least twice with time diversity, receiving and detecting said modulated carrier signal, recognizing times of interference in said detected signal by determining amplitude variations, storing said times of interference, frequency or phase demodulating said received detected signal, storing said demodulated signal, and reconstructing said data from said stored demodulated signal by using said stored times of interference.

2. A radio communication transmission system wherein the intelligence in digital form are impressed onto a radio frequency carrier by means of frequency modulation and/or phase modulation and is transmitted with time diversity so that each intelligence block is transmitted at least twice at different times and with the time spacing known at the receiver, including a receiver including an intermediate frequency stage which produces an input signal, an interference recognition device at said receiver which receives said input signal from said I.F. stage and recognizes the presence of amplitude modulation occurring in the output of said intermediate frequency stage caused by interference, a demodulator at the receiver also receiving said input signal from said I.F. stage and demodulating data therefrom, storage means connected to said demodulator and storing said data, an interference storage means connected to said interference recognition device and recording periods during which interference occurs and a program control receiving inputs from said interference storage means and supplying inputs to said data storage means for reconstructing said data.

3. A radio communication system comprising, a transmitter for transmitting binary coded data information which is frequency or phase modulated on a carrier signal and wherein said data is transmitted at least twice in time diversity with a time spacing which is known, a receiver receiving said modulated carrier signal, an amplitude detector receiving an output of said receiver and detecting amplitude variations which indicate interference in the received data by producing signals indicative of periods of interference and periods free of interference, an interference storage device connected to said amplitude detector and recording periods of interference and periods free of interference, a frequency or phase demodulator receiving an output of said receiver and detecting said coded data, receiver storage means receiving the output data from said demodulator and storing it, and a control means receiving inputs from said interference storage device and said receiver storage means and gating information from said receiver storage means so as to reconstruct the transmitted data.

4. A radio communications system according to claim 3, wherein said data is transmitted in blocks with each data block being redundantly transmitted such that the transmitted data can be reconstituted at the output of said receiver storage means.

5. A radio communications system according to claim 4, wherein said receiver storage means and said interference storage device includes a pair of shift registers.