GB1328558A - Fm pulse compression system for communicat-ons - Google Patents
Fm pulse compression system for communicat-onsInfo
- Publication number
- GB1328558A GB1328558A GB1328558DA GB1328558A GB 1328558 A GB1328558 A GB 1328558A GB 1328558D A GB1328558D A GB 1328558DA GB 1328558 A GB1328558 A GB 1328558A
- Authority
- GB
- United Kingdom
- Prior art keywords
- swept
- signals
- frequency
- network
- rising
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/103—Chirp modulation
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
1328558 Digital transmission systems DEFENCE SECRETARY OF STATE FOR 17 Nov 1971 [17 Nov 1970] 54585/70 Headings H4L and H4P A demodulator for upward swept (1) and downward swept (0) chirp signals consists of: two mixers 12, 13 transposing the input signal into two separate frequency bands which are symmetrical about a selected frequency f 3 , a symmetrical dispersive network 16 having a delay-frequency characteristic also symmetrical about f 3 (A, Fig. 8, not shown), and two filters 17, 18 passing frequencies above (1) and below (0) f 3 respectively. The received signals at 11 sweep through a range of 2# in one or other direction about a centre frequency f 0 , The mixer outputs corresponding to an upward sweep of the received signal, both sweep upwards through 2#, one 12 starting from f 3 and the other 13 finishing at f 3 . Similarly, the mixer outputs sweep downwards, to and from f 3 respectively, for a downward swept received signal. Since the dispersive netwrok introduces a delay which is maximum (T, Fig. 8, not shown) at f 3 and which decreases on either side of f 3 , signals whose frequencies are swept away from f 3 in either direction are compressed to give a significant output from the network 16, while signals swept towards f 3 are expanded to give insignificant outputs from the network 16. Thus a significant output in the upper band f 3 to (f 3 +2#) is produced by upward swept received signals (1's) and a significant output in the lower band f3 to (f 3 - 2#) is produced by 0's. These signals are supplied by detectors 19, 20 to a threshold device 21 which regenerates the D.C. 0 or 1 signal. The dispersive network 16 may be one or a chain (Fig. 7, not shown) of second order all-pass networks (Figs. 3, 4, not shown). In what is said to be a known demodulator (Fig. 1, not shown) two dispersive networks are used having linear delay-frequency characteristics, one of which has a delay falling with rising frequency (C R , Fig. 5, not shown) and the other rising with rising frequency. One network then produces a compressed output for upward swept signals and the other network for downward swept signals. A synthesizer for generating the frequency modulating signal at the transmitter includes a shift register (Fig. 9, not shown) whose successively energized outputs are combined through progressively different resistors (R1 to RN) to give a rising voltage at the input of an amplifier (25). The output of the amplifier is applied to one gate (26), and the inverted (at 28) output is applied to a second gate (27). One or other gate is enabled by a sample and hold circuit 29 in response to a data input, to pass the rising or the falling (inverted) voltage to a voltage controlled oscillator 30.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5458570 | 1971-11-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1328558A true GB1328558A (en) | 1973-08-30 |
Family
ID=10471488
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1328558D Expired GB1328558A (en) | 1971-11-17 | 1971-11-17 | Fm pulse compression system for communicat-ons |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1328558A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2281424B (en) * | 1991-06-14 | 1998-04-29 | Baker Hughes Inc | Method for communicating data in a wellbore |
GB2430590A (en) * | 2005-09-21 | 2007-03-28 | Avago Technologies Wireless Ip | Modulating digital data to a frequency ramp signal for communication with a receiver whose input filter may drift |
GB2475039A (en) * | 2009-10-30 | 2011-05-11 | Wayne Rudd | Communicating information by transmitting chirps in a structure |
-
1971
- 1971-11-17 GB GB1328558D patent/GB1328558A/en not_active Expired
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2281424B (en) * | 1991-06-14 | 1998-04-29 | Baker Hughes Inc | Method for communicating data in a wellbore |
US5850369A (en) * | 1991-06-14 | 1998-12-15 | Baker Hughes Incorporated | Method and apparatus for communicating data in a wellbore and for detecting the influx of gas |
GB2430590A (en) * | 2005-09-21 | 2007-03-28 | Avago Technologies Wireless Ip | Modulating digital data to a frequency ramp signal for communication with a receiver whose input filter may drift |
GB2475039A (en) * | 2009-10-30 | 2011-05-11 | Wayne Rudd | Communicating information by transmitting chirps in a structure |
GB2475039B (en) * | 2009-10-30 | 2013-12-18 | Bios Developments Ltd | Methods for communicating and associated apparatus |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |