公开(公告)号：WO1991008631A1

公开(公告)日：1991-06-13

申请号：PCT/US1990006783

申请日：1990-11-21

Applicant: SCIENTIFIC-ATLANTA, INC.

Inventor： SCIENTIFIC-ATLANTA, INC. ,  PIDGEON, Rezin ,  LITTLE, Frank ,  THOMPSON, Leo

IPC: H04J14/00

CPC classification number: H04N7/22 ,  H04B10/504 ,  H04B10/506 ,  H04J14/0298

Abstract: A plurality of radio frequency channels are separated into two or more contiguous groups of channels, each of such groups occupying less than one octave. A first group of channels occupies a 54 MHz to 106 MHz band, a second band of channels occupies a 108 MHz to 214 MHz band, and optionally, additional channel groups may occupy the bands of 214 MHz through 426 MHz and 426 MHz through 850 MHz. Each sub-band is used to modulate the intensity of the output of a laser (1, 2, 3). Each resulting amplitude modulated light signal is transmitted over an optical link (F1, F2, F3, F4) to a receiving location. Alternatively, the lasers (1, 2, 3) may be selected to generate light at different wavelengths with all outputs transmitted over a single optical link. At the receiving location, each of the optical signals is received and demodulated by a respective individual receiver (51, 52, 53). The demodulated signal is passed through a bandpass filter which reduces harmonics, intermodulation distortions, and noise produced in transmission. The resulting signals are then matched in amplitude before being applied to combiner (69, 70) which converts them back into a single broadband signal. The broadband signal is then processed to reduce discontinuities at the transitions between the sub-bands. All of the baseband television signals can be modulated onto carrier frequencies in the highest sub-band of interest (e.g., in the range of 330 to 550 MHz). Because of the separation of signals provided by multiple optical links (F1, F2, F3, F4), the same carrier frequency may be utilized on each of the links to carry a channel of baseband video information.

公开(公告)号：EP0507799B1

公开(公告)日：1998-07-01

申请号：EP91901147.8

申请日：1990-11-21

Applicant: SCIENTIFIC-ATLANTA, INC.

Inventor： PIDGEON, Rezin ,  LITTLE, Frank ,  THOMPSON, Leo

IPC: H04J14/00 ,  H04J1/00 ,  H04B10/06 ,  H04J14/02 ,  H04B10/14

CPC classification number: H04N7/22 ,  H04B10/504 ,  H04B10/506 ,  H04J14/0298

Abstract: A plurality of radio frequency channels are separated into two or more contiguous groups of channels, each of such groups occupying less than one octave. A first group of channels occupies a 54 MHz to 106 MHz band, a second band of channels occupies a 108 MHz to 214 MHz band, and optionally, additional channel groups may occupy the bands of 214 MHz through 426 MHz and 426 MHz through 850 MHz. Each sub-band is used to modulate the intensity of the output of a laser (1, 2, 3). Each resulting amplitude modulated light signal is transmitted over an optical link (F1, F2, F3, F4) to a receiving location. Alternatively, the lasers (1, 2, 3) may be selected to generate light at different wavelengths with all outputs transmitted over a single optical link. At the receiving location, each of the optical signals is received and demodulated by a respective individual receiver (51, 52, 53). The demodulated signal is passed through a bandpass filter which reduces harmonics, intermodulation distortions, and noise produced in transmission. The resulting signals are then matched in amplitude before being applied to combiner (69, 70) which converts them back into a single broadband signal. The broadband signal is then processed to reduce discontinuities at the transitions between the sub-bands. All of the baseband television signals can be modulated onto carrier frequencies in the highest sub-band of interest (e.g., in the range of 330 to 550 MHz). Because of the separation of signals provided by multiple optical links (F1, F2, F3, F4), the same carrier frequency may be utilized on each of the links to carry a channel of baseband video information.

公开(公告)号：EP0507799A1

公开(公告)日：1992-10-14

申请号：EP91901147.0

申请日：1990-11-21

Applicant: SCIENTIFIC-ATLANTA, INC.

Inventor： PIDGEON, Rezin ,  LITTLE, Frank ,  THOMPSON, Leo

IPC: H04J14 ,  H04B10 ,  H04J1 ,  H04N7

CPC classification number: H04N7/22 ,  H04B10/504 ,  H04B10/506 ,  H04J14/0298

Abstract: On sépare une pluralité de canaux de fréquences radiaux en deux groupes contigus de canaux ou plus, chacun desdits groupes occupant moins d'une octave, un premier groupe de canaux occupe une bande comprise entre 54 MHz et 106 MHz, une seconde bande de canaux occupe une bande comprise entre 108 MHz et 214 MHz et facultativement, des groupes de canaux supplémentaires peuvent occuper les bandes allant de 214 MHz à 426 MHz et 426 MHz à 850 MHz. On utilise chaque sous-bande afin de moduler l'intensité de la sortie d'un laser (1, 2, 3). Chaque signal de lumière modulé en amplitude obtenu est transmis par une liaison optique (F1, F2, F3, F4) à un emplacement de réception. Selon un autre mode de réalisation, on peut sélectionner les lasers (1, 2, 3) afin qu'ils produisent une lumière à différentes longueurs d'ondes, toutes les sorties étant transmises par une seule liaison optique. Au niveau de l'emplacement de réception, chacun des signes optiques est reçu et est démodulé par un récepteur individuel respectif (51, 52, 53). Le signal démodulé est passé dans un filtre passe-bande, lequel réduit les harmoniques, les distorsions d'intermodulation et le bruit produit lors de la transmission. Les signaux obtenus sont ensuite appariés en intensité, avant d'être appliqués à un multiplexeur (69, 70), lequel les reconvertit en un signal à une bande large. Le signal de bande large est ensuite traité afin de réduire les discontinuités au niveau des transitions entre les sous-bandes. Tous les signaux de télévision de bande de base peuvent être modulés sur des fréquences porteuses dans la sous-bande la plus élevée d'intérêt (par exemple, dans la plage comprise entre 350 et 550 MHz). Comme les liaisons optiques multiples (F1, F2, F3, F4) séparent les signaux, la même fréquence porteuse peut être utilisée dans chacune des liaisons afin de porter un canal d'informations vidéo de bande de base.