Multiple-input multiple-output (MIMO) communication system

• US 9,319,257 B2
• Filed: 02/15/2014
• Issued: 04/19/2016
• Est. Priority Date: 02/16/2013
• Status: Active Grant

• Current Assignee: Cable Television Laboratories Incorporated
• Original Assignee: Cable Television Laboratories Incorporated
• Inventors: Campos, Luis Alberto, Andreoli-Fang, Jennifer, Padden, Joey
• Primary Examiner(s): PATEL, DHAVAL V
• Application Number:
  US14/181,640
• Publication Number:
  US 20140233678A1
• Time in Patent Office: 794 Days
• Field of Search: 375/299, 375/260, 375/262, 375/267, 375/232, 375/295, 375/329, 375/340, 455/318, 455/452.1, 455/456.1
• US Class Current: 1/1
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04W 72/00 Local resource management

Abstract

A multiple-input multiple-output (MIMO) capable system is contemplated. The communication system may include a signal processor configured to separate an input stream into multiple signal paths to facilitate simultaneous transport through a communication medium. The capability to simultaneously transmit multiples signal paths may be beneficial in order to maximize throughput and/or minimize expense.

Claims

1. A multiple-input multiple-output (MIMO) signal processor comprising:

a baseband processor configured to multiplex an input signal into at least a first signal part, a second signal part, a third signal part and a fourth signal part;

a radio frequency integrated circuit (RFIC) configured to transmit the first signal part at a first frequency, the second signal part at a second frequency, the third signal part at a third frequency and the fourth signal part at a fourth frequency, each of the first, second, third and fourth frequencies being different;

a front end including a summation device configured to join the first, second, third and fourth signal parts into an output signal following transmission from the RFIC; and

a laser configured to transmit the output signal over at least one of a wireline communication medium and an optical communication medium, the laser modulating each of the first, second, third and fourth signal parts included in the output signal according to the corresponding first, second, third and fourth frequencies so as to provided frequency diverse long-haul transport of the output signal.

2. The signal processor of claim 1 wherein the front end includes a first filter for filtering the output signal, and thereby each of the first, second, third and fourth signal parts included therein, prior to output to the laser.

3. The signal processor of claim 2 wherein the front end includes a first amplifier for amplifying the output signal, and thereby each of the first, second, third and fourth signal parts included therein, after being filtered with the first filter and prior to output to the laser.

4. The signal processor of claim 3 wherein the front end includes a second filter, a third filter, a fourth filter and a fifth filter, the second filter filtering the first signal part prior to transport to the summation device, the third filter filtering the second signal part prior to transport to the summation device, the fourth filter filtering the third signal part prior to transport to the summation device and the fifth filter filtering the fourth signal part prior to transmission to the summation device.

5. The signal processor of claim 4 wherein the front end includes a second amplifier, a third amplifier, a fourth amplifier and a fifth amplifier, the second amplifier amplifying the first signal part after filtering with the second filter and prior to transport to the summation device, the third amplifier amplifying the second signal part after filtering with the third filter and prior to transport to the summation device, the fourth amplifier amplifying the third signal part after filtering with the fourth filter and prior to transport to the summation device and the fifth amplifier amplifying the fourth signal part after filtering with the fifth filter and prior to transmission to the summation device.

6. The signal processor of claim 5 wherein the filtering performed with each of the first, second, third, fourth and fifth filters and the amplifying performed with each of the first, second, third, fourth and fifth amplifiers are each individually controllable as a function of instructions received from a master controller, the master controller independently setting at least one of a passband for each of the first second, third, fourth and fifth filters and an amount of gain for each of the first second, third, fourth and fifth amplifiers according to a corresponding first set of values when at least a portion of the output signal is to travel through a first path within the at least one of the wireline communication medium and the optical communication medium and according to a corresponding second set of values when at least a portion of the output signal is to travel through a second path within the at least one of the wireline communication medium and the optical communication medium, the second path being different than the first path and the second set of values being different than the first set of values.

7. A multiple-input multiple-output (MIMO) signal processor comprising:

a baseband processor configured to multiplex an input signal into at least a first signal part, a second signal part, a third signal part and a fourth signal part;

a radio frequency integrated circuit (RFIC) configured to transmit the first signal part at a first frequency, the second signal part at a second frequency, the third signal part at a third frequency and the fourth signal part at a fourth frequency, each of the first, second, third and fourth frequencies being different;

a front end including a summation device configured to join the first, second, third and fourth signal parts into an output signal following transmission from the RFIC; and

wherein the baseband processor outputs each of the first, second, third and fourth signal parts at a fifth frequency and a digital interface of the RFIC thereafter separates each of the first, second, third and fourth signal parts according to digital in-phase and quadrature phase components such that the digital interface generates first digital in-phase and quadrature phase components for the first signal part, second digital in-phase and quadrature phase components for the second signal part, third digital in-phase and quadrature phase components for the third signal part and fourth digital in-phase and quadrature phase components for the fourth signal part.

8. The signal processor of claim 7 wherein the RFIC includes a separate digital-to-analog converter (DAC) for converting each of the first, second, third and fourth digital in-phase and quadrature phase components following output from the digital interface into corresponding first, second, third and fourth analog in-phase and quadrature phase components.

9. The signal processor of claim 8 wherein the RFIC includes a first oscillator, a second oscillator, a third oscillator and a fourth oscillator each individually controllable with a master controller, the master controller controlling the first oscillator according to a first oscillation sufficient for facilitating conversion of the first signal part from the fifth frequency to the first frequency, the second oscillator according to a second oscillation sufficient for facilitating conversion of the second signal from the fifth frequency to the second frequency, the third oscillator according to a third oscillation sufficient for facilitating conversion of the third signal part from the fifth frequency to the third frequency and the fourth oscillator according to a fourth oscillation sufficient for facilitating conversion of the fourth signal part from the fifth frequency to the fourth frequency, whereby each of the first, second, third and fourth oscillations are different.

10. The signal processor of claim 9 wherein the RFIC includes a separate mixer for each of the analog first, second, third and fourth in-phase and quadrature phase components, each mixer operating with no more than one of the first, second, third and fourth oscillators to facilitate transmitting the corresponding one of the analog first, second, third and fourth in-phase and quadrature phase components at the corresponding first, second, third and fourth frequencies, each analog in-phase and quadrature phase component thereafter being joined to form the first, second, third and fourth signal parts as transmitted at the first, second, third and fourth frequencies to the front end.

11. The signal process of claim 9 wherein the master controller selects the first, second, third and fourth frequencies as a function of spectrum available within a wired communication medium used to facilitate long-haul transport of the output signal from the front end.

12. The signal processor of claim 9 wherein the signal processor is configured to receive the input signal at the fifth frequency as a non-frequency diverse signal issued from at least one of:

a cellular communication system, the input signal thereby being derived from a cellular signal transmitted over the cellular communication system;

an Internet Service Provider (ISP), an application service provider or an over the top service provider, the input signal thereby being derived from data transmitted through one of the service providers; and

a cable television service provider system, the input signal thereby being derived from television transmissions carried over the cable television service provider system.

13. The signal processor of claim 11 wherein the master controller selects the first, second, third and fourth frequencies to be within a first frequency range when the output signal is destined for a first service area and to be within a second frequency range when the output signal is destined for a second service area, the second frequency range being outside of the first frequency range.

16. The signal processor of claim 11 wherein the master controller selects the first, second, third and fourth frequencies to be within a first frequency range when the output signal is in a downlink direction and to be within a second frequency range when the output signal is in an uplink direction, the second frequency range being outside of the first frequency range.

14. A method of facilitating signal transmissions comprising:

receiving an input signal desired for transmission to one or more service areas;

multiplexing the input signal into at least a plurality of signal parts;

modulation mapping each of the plurality of signal parts after the multiplexing;

orthogonal frequency division multiplexing (OFDM) processing each of the plurality of signal parts after the modulation mapping;

determining a plurality of center frequencies for the plurality of signal parts as a function of the one or more service areas such that the center frequency for each of the plurality of signal parts is different;

instructing a plurality of local oscillators to facilitate mixing the plurality of signal parts at one of the plurality of center frequencies following the OFDM processing;

transmitting each of the plurality of signal parts for long-haul transmission to the one or more service areas over at least one of a wireline communication medium and an optical communication medium after the mixing.

15. The method of claim 14 further comprising dynamically amplifying the plurality of signal parts as a function of instructions received from a master controller, the dynamic amplification characterized by adjusting gain and/or tilt (frequency dependent gain) for one of more of the plurality of signals parts as a function of losses associated with a path intended to be traveled for the corresponding one of the plurality of signals to reach the one or more service areas, including adjusting the gain and/or tilt for at least one of the plurality of signal parts after initially setting the corresponding gain and/or tilt when the corresponding signal path changes.

17. A multiple-input multiple-output (MIMO) signal processor comprising:

a baseband processor configured to multiplex an input signal into at least a first signal part and a second signal part;

a master controller configured to;

i) determine a first service area for the first signal part and a second service area for the second signal part; and

ii) determine a first frequency suitable for use in the first service area and a second frequency suitable for use in the second service area;

a radio frequency integrated circuit (RFIC) configured to transmit the first signal part at the first frequency and the second signal part at the second frequency, the RFIC including a first oscillator for mixing the first signal part and a second oscillator for mixing the second signal part; and

a front end configured to combine the first signal part and the second signal part into an output signal for output put to a radio frequency (RF) combiner.

18. The signal processor of claim 17 wherein the master controller instructs the first and second oscillators to facilitate mixing the first and second signal parts such that the first frequency is different from the second frequency.

19. The signal processor of claim 18 wherein the master controller selects the first frequency from a plurality of frequencies licensed within the first service area and selects the second frequency from a plurality of frequencies licensed in the second services areas such that the first and second frequencies are dynamically and individually selectable according to the first and second services areas associated therewith.