Boots – shoes – and leggings
Patent
1991-06-17
1993-04-13
Nguyen, Long T.
Boots, shoes, and leggings
385 24, 3401462, G06F 104, G06E 102
Patent
active
052028453
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND
I. Field of the Invention
The present invention relates to an optical signal processor and to a method of processing optical data.
II. Prior Art and Other Considerations
In communication systems spread spectrum techniques have been used and it is though that such techniques could offer several advantages in local area networks. In particular, spread spectrum optical communication techniques based on white light interference have been known for some time and recently these techniques have been used in coherence multiplexed optical fibre sensor systems.
Recently a spread spectrum technique, referred to as code division multiple access (CDMA) has been described for use with local area networks. In this scheme each user is assigned orthogonal codes, which results in a substantial increase of the bandwidth of the transmitted signal. However, the bandwidth requirements of this technique can only be supported by wide bandwidth channels such as a occur in fibre-optics, as well as requiring wide bandwidth signal processors at the receiver. Conventional receivers for CDMA use electronic processors, however, these are slow when compared with optical systems and also can be effected by electrical noise. It is desirable to provide an all-fibre and integrated optical processor which could facilitate and permit all optical processing so that maximum potential of such techniques can be realised.
SUMMARY
It is an object of the present invention to provide a signal processing system and a method and apparatus for processing optical signals which obviates or mitigates at least one of the aforementioned problems.
This is achieved by providing an optical processing element based on at least two optical couplers which are connected so that the principal channels are connected in series with a time delay of a predetermined value in the principal channel between adjacent optical coupling units. The optical coupling units are formed into stages and the number of optical coupling units per stage determines further coding of each bit of the input optical signal or code sequence. In other words, if the input code is M-bits long then M optical coupler stages are required to process this code and determine whether the code matches with the preset code sequence. Stages can be coupled together to process a sequence of optical pulses corresponding in number to the number of optical coupling stages in the system and the outputs of each stage are coupled via optical switches to an optical summing device to simultaneously process the coded data and determine whether the processing has resulted in matching or mismatching of data.
In one embodiment the data is coded in accordance with a Gold code sequence of M-bits length and two optical coupling units per stage of M stages are provided in the optical processing system.
According to a first aspect of the present invention there is provided an optical processing device for use in an optical communication system to determine the matching or mismatching of data, said optical processing device comprising at least two optical coupler units having a principal channel separated by a time delay T and a coupled channel having a minimal time delay in comparison to time delay T, each optical coupling unit being presetable to enable or to inhibit optical coupling of the input signal, the principal or coupled channels of the optical coupler being serially connected and the output of the optical processing device being taken from the optically coupled channel.
Preferably in the optical processing there are 2 optical coupler units having a principal channel with a time delay T between said coupler units such that for each optical input digit there is provided an optical output signal consisting of 2 outputs separated by time T.
Preferably the output of the optical processing device is coupled to optical switch means, said optical switch means being presetable to provide an output signal when the optical input signal exceeds a threshold value.
According to another aspect of the present inventio
REFERENCES:
patent: 3245035 (1966-04-01), English
patent: 4604707 (1986-08-01), Yamashita et al.
patent: 4859019 (1989-08-01), Bevan
M. Shabeer et al., "Fiber-Optic Bipolar Tap Implementation Using An Incoherent Optical Source", Optics Letters, vol. 12, No. 9, Sep. 1987, pp. 726-728.
A. Tal et al., "Optical Residue Arithmetic Computer With Programmable Computation Modules", Applied Optics, vol. 18, No. 16, Aug. 1979 pp. 2812-2823.
Andonovic Ivan
Culshaw Brian
Shabeer Mohammed
British Telecommunications public limited company
Nguyen Long T.
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