Cable interface for data and power supply

• US 6,563,801 B2
• Filed: 01/26/2000
• Issued: 05/13/2003
• Est. Priority Date: 07/31/1997
• Status: Expired due to Term

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Makinen, Jarmo, Raimovaara, Antti, Hamalainen, Ville
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): PEZZLO, JOHN
• Application Number:
  US09/490,797
• Publication Number:
  US 20030007462A1
• Time in Patent Office: 1,203 Days
• Field of Search: 370/276, 370/282, 370/286, 370/287, 370/288, 370/289, 370/290, 370/297, 375/140, 375/344, 375/345, 375/346, 375/349, 375/350, 375/371, 375/376, 379/338, 379/340, 379/344, 379/345, 379/347, 379/348, 379/398, 379/400, 379/402, 379/405, 379/413, 379/406.02
• US Class Current: 370/276
• CPC Class Codes: H04B 3/03 Hybrid circuits for transceivers H04B1/52, H04B1/58
• CPC Class Codes: H04B 3/04 Control of transmission; Equalising
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54
• CPC Class Codes: H04L 25/10 Compensating for variations in line balance
• CPC Class Codes: H04L 5/1423 for simultaneous baseband signals
• CPC Class Codes: H04N 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

The cable interface unit in accordance with the invention allows use of the same wire in one cable both for base-band transmission of data between telecommunication equipment in full duplex form and also for transmission of an operating voltage (V) from one device to another. In the transmission unit, data is transmitted through a hybrid connection (41) to a cable (23). After the hybrid connection, the operating voltage (V) is also brought to the cable with the aid of a diplexer (44). The hybrid connection separates the arriving data and conducts it to the receiver, where the data is shaped in an analog manner by correcting level distortions and thereupon in the digital signal processing a DECISION is made on what the received symbol is.

Claims

1. A method of transmitting information between units of a divided radio link, both units containing means of transmitting information to a cable and of receiving information arriving from the cable, the method comprising:

applying a supply DC voltage V via a diplexer to the cable at one end of the cable and extracting the supply DC voltage V from the cable via a diplexer at an opposite end of the cable;

supplying a base band transmission signal to a hybrid circuit which transmits the base band transmission signal via at least one of the diplexers to the cable;

conducting a received base band signal carrying information of an original signal arriving from the cable via at least one of the diplexers to said hybrid circuit, which transmits the received base band signal to a receiver; and

shaping the received base band signal using both analog and digital signal processing in order to form a representation of the original signal, wherein base band transmission and received signals travel in full duplex form in the same cable as the supply DC voltage V.

2. The method as defined in claim 1, wherein supplying the base band transmission signal comprises:

inverting the base band transmission signal;

storing temporarily in a buffer the inverted and non-inverted transmission signals, from which they are clocked out at the same time;

supplying unchanged to the cable wire the non-inverted transmission signal;

supplying the inverted and non-inverted baseband transmission signals to a matching network, where a virtual zero point is arranged and the inverted and non-inverted base band transmission signals abort one another.

3. The method as defined in claim 1, further comprising:

converting the received base band signal in an AD converter into a digital signal;

comparing a symbol value obtained from the AD converter to a preset value representing a DC level, whereupon a decision is made on whether the received signal is logical zero or logical one, wherein the decision represents the original signal; and

correcting the DC level with a correction value based on the symbol value and the preset value.

4. The method as defined in claim 3, further comprising forming digital signal processing controls which are needed in the analog shaping by using a representation of the original signal and its error.

5. The method as defined in claim 1, wherein conducting the received base band signal comprises:

supplying the received signal arriving from the cable to a matching network; and

supplying the received signal from a virtual zero point to the receiver.

6. A cable interface unit for transmitting information from a unit in a divided radio link to a cable and for transmitting information received from the cable to the unit, comprising:

a hybrid circuit including;

an inverter for inverting a digital base band transmission signal;

a buffer for temporarily storing both a non-inverted base band transmission signal and an inverted base band transmission signal, and for clocking stored signals out at the same time, wherein the non-inverted base band transmission signal is functionally connected to the cable; and

a matching network connected to the output of the buffer, the matching network including a virtual zero point where the inverted and non-inverted base band transmission signals arriving from the buffer abort one another and from which a received base band signal is supplied to a receiver.

7. The cable interface unit as defined in claim 6, further comprising a diplexer connected to a cable on the one hand and to the hybrid circuit on the other hand, the diplexer including a terminal via which an operating voltage is applied to the cable, the operating voltage being intended for a telecommunication device located at an opposite end of the cable, through which the operating voltage is extracted from the cable, said operating voltage being supplied by a telecommunication device located at the opposite end of the cable.

8. The cable interface unit as defined in claim 6, further comprising a digital DC level regeneration loop that receives symbols obtained by sampling an analog signal in an AD converter and compares symbol values to a preset value representing a digital DC level, whereupon a decision signal is produced and a level of the decision signal is used to determine whether the received signal is a logical 1 or 0.

9. The cable interface unit as defined in claim 8, wherein the receiver comprises:

a first control generation loop which in response to the level of the regenerated signal and to its error forms a first control for automatic gain control adjustment;

a second control generation loop which in response to the level of the regenerated signal and to its error forms a second control for frequency adjustment; and

a phase locked loop which in response to the level of the regenerated signal and to its error forms a synchronised clock frequency in the received signal.

10. A divided radio link including an indoor unit, which performs processing of a received signal and transmits a transmission signal to an outdoor unit, the outdoor unit transmits the transmission signal received from the indoor unit to an antenna and the signal received by the antenna is transmitted to the indoor unit, the indoor and outdoor units comprising:

a diplexer for applying a supply DC voltage V to or extracting a supply DC voltage V from a cable, and for conducting a signal received from the cable to a virtual zero point;

a buffer for storing an inverted and non-inverted digital baseband transmission signals and clocking out stored signals at the same time;

wherein the non-inverted baseband transmission signal is applied via the diplexer to the cable;

a matching network for receiving the inverted and non-inverted digital baseband transmission signals from the buffer, the matching network having a point where said baseband transmission signals cancel each other, said point forming the virtual zero point;

analog and digital signal processing means for shaping the received signal in order again to form a regenerated original signal.

11. The divided radio link as defined in claim 10, wherein control signals between the indoor unit and the outdoor unit travel as separate frames in the same cable as the transmission signal, the received signal, and the supply DC voltage V.

12. The divided radio link as defined in claim 10, wherein control signals between the indoor unit and the outdoor unit, the transmission signal, the received signal, and the supply DC voltage V travel in the same cable, the control signals having a same frequency but a smaller amplitude than the transmission signal and the received signal.