ORTHOGONAL FREQUENCY DIVISION MULTIPLEX MODEM CIRCUIT

• US 20110038403A1
• Filed: 10/27/2010
• Published: 02/17/2011
• Est. Priority Date: 06/14/2000
• Status: Active Grant

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: ICHIHARA, Masaki, FURUYA, Yukitsuna
• Granted Patent: US 8,335,153 B2
• Time in Patent Office: Days
• US Class Current: 375/222
• CPC Class Codes: H04L 27/183 Multiresolution systems
• CPC Class Codes: H04L 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488
• CPC Class Codes: H04L 27/3488 Multiresolution systems
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26

Abstract

To provide an orthogonal frequency division multiplex modem circuit which can multiplex signals, whose bit rates and QoS are different from one another, and can transmit the signals via one OFDM line. A serial/parallel converter converts input signals into a complex parallel signal respectively, and a sub carrier and a modulation system are assigned every communication channel. A randomizer changes the alignment sequence of the signal, a discrete inverse Fourier transformer processes the signal, a parallel/serial converter converts the signal into a serial signal, and a transmitter performs the orthogonal modulation of the signal to output the signal from an antenna. A receiver performs orthogonal demodulation of the signal received with an antenna, a serial/parallel converter converts the signal into a parallel signal, and a discrete Fourier transformer processes the parallel signal. In addition, a de-randomizer restores the alignment sequence of the subcarriers into the original condition, and a parallel/serial converter decodes and outputs the signal.

Claims

1. A transmitter for an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein said communication channels are adapted for transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, and wherein one or more subcarriers are assigned to each of a plurality of the communication channels and the number of the subcarriers assigned to each of said plurality of the communication channels is determined according to the bit rate, QoS and/or priority of the communication channel.

2. The transmitter according to claim 1, wherein the assignment of the number of the subcarriers and/or the modulation system to the respective communication channels is adaptively performed.

3. The transmitter according to claim 1, wherein the number of the subcarriers and/or the modulation system is determined such that the symbol rates of all subcarriers are set to the same rate.

4. A receiver, for an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein said communication channels are adapted for transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, and wherein one or more subcarriers are assigned to each of a plurality of the communication channels and the number of the subcarriers assigned to each of said plurality of the communication channels is determined according to the bit rate, QoS and/or priority of the communication channel.

5. The receiver according to claim 4, wherein the assignment of the number of the subcarriers and/or the modulation system to the respective communication channels is adaptively performed.

6. The receiver according to claim 4, wherein the number of the subcarriers and/or the modulation system is determined such that the symbol rates of all subcarriers are set to the same rate.

7. An orthogonal frequency division multiplex modem system comprising:

a transmitter in a transmission system for an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a;

plurality of communication channels, wherein said communication channels are adapted for transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, and wherein one or more subcarriers are assigned to each of a plurality of the communication channels and the number of the subcarriers assigned to each of said plurality of the communication channels is determined according to the bit rate, QoS and/or priority of the communication channel;

an

a receiver in a receiving system for an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein said communication channels are adapted for transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, and wherein one or more subcarriers are assigned to each of a plurality of the communication channels and the number of the subcarriers assigned to each of said plurality of the communication channels is determined according to the bit rate, QoS and/or priority of the communication channel.

8. A transmission method for an orthogonal frequency division multiplex communication method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, said communication channels transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, said method comprising the step of assigning one or more subcarriers to each of a plurality of the communication channels and the step of determining the number of the subcarriers assigned to each of said plurality of the communication channels according to the bit rate, QoS and/or priority of the respective communication channel.

9. The transmission method according to claim 8, comprising the step of adaptively assigning the number of the subcarriers and/or the modulation system to the respective communication channels.

10. The transmission method according to claim 8, comprising the step of determining the number of the subcarriers and/or the modulation system such that the symbol rates of all subcarriers are set to the same rate.

11. A receiving method for an orthogonal frequency division multiplex communication method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication, channels, said communication channels transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, said method comprising the step of assigning one, or more subcarriers to each of a plurality of the communication channels and the step of determining the number of the subcarriers assigned to each of said plurality of the communication channels according to the bit rate, QoS and/or priority of the respective communication channel.

12. The receiving method according to claim 11, comprising the step of adaptively assigning the number of the subcarriers and/or the modulation system to the respective communication channels.

13. The receiving method according to claim 11, comprising the step of determining the number of the subcarriers and/or the modulation system such that the symbol rates of all subcarriers are set to the same rate.

14. An orthogonal frequency division multiplex communication method comprising:

a transmission method for an orthogonal frequency division multiplex communication method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, said communication channels transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, said method comprising the step of assigning one or more subcarriers to each of a plurality of the communication channels and the step of determining the number of the subcarriers assigned to each of said plurality of the communication channels according to the bit rate, QoS and/or priority of the respective communication channel; and

a receiving method for an orthogonal frequency division multiplex communication method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, said communication channels transmitting and receiving with different bit rates, Quality of Service QoS and/or priorities, said method comprising the step of assigning one or more subcarriers to each of a plurality of the communication channels and the step of determining the number of the subcarriers assigned to each of said plurality of the communication channels according to the bit rate, QoS and/or priority of the respective communication channel.