Systems and method for orthogonal frequency divisional multiplexing

• US 7,881,181 B2
• Filed: 10/29/2007
• Issued: 02/01/2011
• Est. Priority Date: 02/06/1995
• Status: Expired due to Fees

• Current Assignee: HTC Corporation
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Dapper, Mark J., Geile, Michael J., Hill, Terrance J., Roberts, Harold A., Anderson, Brian D., Brede, Jeffrey, Wadman, Mark S., Kirscht, Robert J., Herrmann, James J., Fort, Michael J., Buska, Steven P, Solum, Jeff, Enfield, Debra Lea, Berg, Darrell, Smigelski, Thomas, Tucker, Thomas C, Hall, Joe, Logajan, John M., Boualouang, Somvay, Lou, Heng, Elpers, Mark, Downs, Matt, Ferris, Tammy, Opoczynski, Adam, Russell, David S, Nelson, Calvin G, Samant, Niranjan R, Chiappetta, Joseph F, Sarnikowski, Scott
• Primary Examiner(s): Jain, Raj K
• Application Number:
  US11/927,428
• Publication Number:
  US 20080225691A1
• Time in Patent Office: 1,191 Days
• Field of Search: None
• US Class Current: 370/206
• CPC Class Codes: G06F 17/14 Fourier, Walsh or analogous domain transformations , e.g. Laplace, Hilbert, Karhunen-Loeve, transforms for correlation function computation G06F17/156; spectrum analysers G01R23/16
• CPC Class Codes: G06F 17/142 Fast Fourier transforms, e.g. using a Cooley-Tukey type algorithm
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04H 20/69 Optical systems
• CPC Class Codes: H04H 20/77 using carrier waves
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04H 20/79 using downlink of the CATV systems, e.g. audio broadcast via CATV network
• CPC Class Codes: H04H 20/80 having frequencies in two or more frequency bands, e.g. medium wave and VHF
• CPC Class Codes: H04H 60/11 Arrangements for counter-measures when a portion of broadcast information is unavailable
• CPC Class Codes: H04H 60/86 accessed over CATV networks
• CPC Class Codes: H04H 60/96 CATV systems for accessing the Internet H04H60/86
• CPC Class Codes: H04H 60/97 using uplink of the CATV systems
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/255 based on redundancy of transmitted data, transmission path or transmitting source
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0045 : Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 : Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0071 : Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/24 : Testing correct operation
• CPC Class Codes: H04L 12/10 : Current supply arrangements
• CPC Class Codes: H04L 12/12 : Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 12/2801 : Broadband local area networks
• CPC Class Codes: H04L 12/44 : Star or tree networks
• CPC Class Codes: H04L 2001/0093 : Point-to-multipoint
• CPC Class Codes: H04L 2027/0036 : using a recovered symbol clock
• CPC Class Codes: H04L 2027/0057 : quadrature phase
• CPC Class Codes: H04L 2027/0067 : Phase error detectors
• CPC Class Codes: H04L 25/03866 : using scrambling
• CPC Class Codes: H04L 27/2601 : Multicarrier modulation systems
• CPC Class Codes: H04L 27/2614 : Peak power aspects
• CPC Class Codes: H04L 27/2631 : with polyphase implementation
• CPC Class Codes: H04L 27/2634 : Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/2652 : with polyphase implementation
• CPC Class Codes: H04L 27/26524 : Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/2654 : Filtering per subcarrier, e.g. filterbank multicarrier [FBMC]
• CPC Class Codes: H04L 27/2655 : Synchronisation arrangements
• CPC Class Codes: H04L 27/2657 : Carrier synchronisation
• CPC Class Codes: H04L 27/2662 : Symbol synchronisation
• CPC Class Codes: H04L 27/34 : Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 41/0213 : Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/064 : involving time analysis
• CPC Class Codes: H04L 41/0896 : Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 43/00 : Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/022 : by sampling
• CPC Class Codes: H04L 43/067 : using time frame reporting
• CPC Class Codes: H04L 43/0811 : by checking connectivity
• CPC Class Codes: H04L 43/0817 : by checking functioning
• CPC Class Codes: H04L 43/0823 : Errors, e.g. transmission errors
• CPC Class Codes: H04L 43/0829 : Packet loss
• CPC Class Codes: H04L 43/0847 : Transmission error
• CPC Class Codes: H04L 43/0852 : Delays
• CPC Class Codes: H04L 43/0858 : One way delays
• CPC Class Codes: H04L 43/0864 : Round trip delays
• CPC Class Codes: H04L 43/0882 : Utilisation of link capacity
• CPC Class Codes: H04L 43/16 : Threshold monitoring
• CPC Class Codes: H04L 5/0007 : the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 : Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 : allocation of payload
• CPC Class Codes: H04L 5/023 : Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/14 : Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/143 : for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1484 : operating bytewise
• CPC Class Codes: H04M 7/006 : Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 9/027 : Frequency division multiplex systems
• CPC Class Codes: H04N 21/2221 : being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/2383 : Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2385 : Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2402 : Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/4382 : Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/6118 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6137 : involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/6168 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 : Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/22 : Adaptations for optical transmission
• CPC Class Codes: H04W 24/00 : Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/08 : Testing, supervising or monitoring using real traffic
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprises: a receiver configured to receive a waveform comprising a plurality of spectrally overlapping carrier signals from at least two of a plurality of remotes, the carrier signals are modulated using an inverse Fourier transform; a transmitter; a processor coupled to the transmitter, the processor outputs data for transmission to the transmitter, the processor applies an inverse Fourier transform to the data provided to the transmitter; a controller programmed to instruct the transmitter to transmit timing adjustments to the at least two of the plurality of remotes, the timing adjustments instruct the at least two of the plurality of remotes to adjust transmission timing so that transmitted symbols associated with frames of a predetermined multiframe structure are received in sequence from the at least two of the plurality of remotes based on the structure.

Claims

1. A remote service unit using minimum allocations in a multipoint-to-point communication system, the remote service unit comprising:

a transceiver communicatively coupled with a host unit in a multipoint-to-point configuration, the transceiver configured to communicate with the host unit via a composite orthogonal frequency division multiplexing (OFDM) waveform of adjacent spectrally overlapping sub-carriers, wherein the transceiver further includes;

at least one converter generating an analog signal based on a stream of time domain in-phase and quadrature phase data; and

a radio frequency transmitter for transmitting a radio frequency signal based on the analog signal;

a multi-carrier modem coupled to the transceiver and configured to modulate upstream payload data onto a plurality of OFDM sub-carriers transmitted by the transceiver, the multi-carrier modem synchronized with the host unit such that the upstream payload data transmitted by the transceiver and other upstream OFDM signals from other transceivers received at the host unit combine to form the composite OFDM waveform, wherein the multi-carrier modulator further includes;

at least one symbol mapper that maps data into symbols using quadrature amplitude modulation (QAM) symbol mapping and phase-shift keying (PSK) symbol mapping; and

a Fast Fourier Transform (FFT) engine, between the at least one symbol mapper and the transceiver, that receives a frame of parallel data, the Fast Fourier Transform (FFT) engine generating time domain in-phase and quadrature phase data from the parallel data;

wherein the remote unit receives channel allocations from the host unit, wherein whenever a channel allocation is made for transport of upstream payload data, the channel allocation provides a plurality of OFDM sub-carriers.

2. The remote service unit of claim 1, wherein the transceiver further comprises a wireless radio frequency transmitter for transmitting a radio frequency signal comprising the plurality of distinct OFDM subcarriers.

3. The remote service unit of claim 1, wherein the transceiver comprises:

a transmitter component; and

a receiver component.

4. The remote service unit of claim 1, wherein the OFDM sub-carriers are selected based on an allocation received from the host unit, wherein each allocation received for transmitting upstream payload to the host unit comprises at least a plurality of contiguous OFDM subcarriers within the composite OFDM waveform.

5. The remote service unit of claim 1, wherein the remote service unit uses the phase-shift keying (PSK) symbol mapping when transmitting control data to the host unit.

6. The remote service unit of claim 1, wherein the remote service unit receives the channel allocation based at least in part on information about the data to be transmitted by the remote service unit.

7. The remote service unit of claim 1, wherein the synchronization of the remote service unit OFDM sub-carriers in time is at least in part based on the remote service unit making timing adjustments to its upstream transmissions to the host unit to equalize a round trip delay of transmissions between the remote service unit and the host unit with transmissions between at least one of the other transceivers and the host unit.

8. The remote service unit of claim 1, wherein the synchronization of the remote service unit OFDM sub-carriers in time is at least in part based on the remote service unit making timing adjustments to its upstream transmissions based on information received from the host unit to align at the host unit multiframes transmitted by the remote service unit with multiframes transmitted to the host unit by at least one of the other transceivers.

9. The remote service unit of claim 1, wherein the remote service unit repeats a follow-up synchronization procedure to maintain timing synchronization within the composite OFDM waveform.

10. The remote service unit of claim 1, wherein the OFDM waveform is a frequency spectrum divided into at least 480 orthogonal sub-carriers.

11. The remote service unit of claim 1, wherein the remote service unit uses a data modulation technique wherein a symbol generated by the symbol mapper is modulated onto a single orthogonal sub-carrier.

12. The remote service unit of claim 1, wherein the multicarrier modulator further includes a component between the symbol mapper and the FFT engine, the component receiving symbols generated by the symbol mapper and outputting the parallel data to the FFT engine.

13. The remote service unit of claim 12, wherein the component is a buffer.