Using OFDM to correct distortions in ultra-wide-band radios operating over flat millimeter-wave channels

1. A Point-to-Point communication system, comprising:

a millimeter-wave channel having a substantially flat channel transfer function between a first frequency of millimeter-waves and a second frequency of millimeter-waves, the two frequencies are separated by at least 500 MHz;

a transmission system comprising an Orthogonal Frequency Division Multiplexing (OFDM) modulator configured to output an OFDM signal having a bandwidth of at least 100 MHz, and a radio transmitter having a substantially non-flat transmission transfer function denoting a difference of at least 4 dB between a highest magnitude and a lowest magnitude of a frequency response of the radio transmitter over the bandwidth of the OFDM signal, the radio transmitter configured to up-convert the OFDM signal into a millimeter-wave signal located between the first frequency and the second frequency, and to transmit the millimeter-wave signal via the millimeter-wave channel; and

a reception system comprising a radio receiver having a substantially non-flat reception transfer function denoting a difference of at least 4 dB between a highest magnitude and a lowest magnitude of a frequency response of the radio receiver over the bandwidth of the OFDM signal, the radio receiver configured to receive the millimeter-wave signal via the millimeter-wave channel and down-convert the millimeter-wave signal into a reconstruction of the OFDM signal having a bandwidth of at least 100 MHz, and an OFDM de-modulator configured to compensate for the substantially non-flat transmission transfer function and the substantially non-flat reception transfer function, by de-modulating the reconstruction of the OFDM signal.

2. The Point-to-Point communication system of claim 1 , wherein the millimeter-wave channel is a wireless channel comprising a first directional antenna through which the millimeter-wave signal is transmitted, and a second directional antenna through which the millimeter-wave signal is received, and combined gain of the first directional antenna and the second directional antenna is at least 50 dBi, causing the millimeter-wave channel to have the substantially flat channel transfer function between the first frequency and the second frequency.

3. The Point-to-Point communication system of claim 1 , wherein the millimeter-wave channel is a waveguide through which the millimeter-wave signal is transmitted, having the substantially flat channel transfer function between the first frequency and the second frequency.

4. The Point-to-Point communication system of claim 1 , wherein the substantially flat channel transfer function of the millimeter-wave channel is flat to a degree that does not require the use of an OFDM modulator and an OFDM de-modulator to facilitate communication over the millimeter-wave channel.

5. The Point-to-Point communication system of claim 4 , wherein the millimeter-wave channel is a wireless channel comprising a first directional antenna through which the millimeter-wave signal is transmitted, and a second directional antenna through which the millimeter-wave signal is received, and combined gain of the first directional antenna and the second directional antenna is at least 50 dBi, causing the millimeter-wave channel to have the substantially flat channel transfer function between the first frequency and the second frequency.

6. The Point-to-Point communication system of claim 5 , wherein the second millimeter wave frequency is between 50 GHz and 100 GHz.

7. The Point-to-Point communication system of claim 5 , wherein the OFDM signal having a bandwidth of at least 100 MHz is used to transmit data over the millimeter-wave channel at a rate of over 100 Mbps.

8. The Point-to-Point communication system of claim 5 , wherein the OFDM signal having a bandwidth of at least 100 MHz has a bandwidth of at least 200 MHz, and is used to transmit data over the millimeter-wave channel at a rate of over 200 Mbps.

9. The Point-to-Point communication system of claim 5 , wherein the OFDM signal having a bandwidth of at least 100 MHz has a bandwidth of at least 500 MHz, and is used to transmit data over the millimeter-wave channel at a rate of over 500 Mbps.

10. The Point-to-Point communication system of claim 1 , wherein the substantially flat channel transfer function is a transfer function having a difference of at most two dB between the highest magnitude and lowest magnitude of the transfer function in the range between the first frequency and the second frequency.

11. The Point-to-Point communication system of claim 10 , wherein the substantially non-flat transmission transfer function is a transfer function having a difference of at least 4 dB between the highest magnitude and lowest magnitude of the transfer function in the range of the at least 100 MHz.

12. The Point-to-Point communication system of claim 10 , wherein the substantially non-flat reception transfer function is a transfer function having a difference of at least 4 dB between the highest magnitude and lowest magnitude of the transfer function in the range of the at least 100 MHz.

13. The Point-to-Point communication system of claim 1 , wherein the radio transmitter is a Radio Frequency Integrated Circuit (RFIC), having a substantially non-flat transmission transfer function as a result of being an Integrated Circuit.

14. The Point-to-Point communication system of claim 1 , wherein the radio receiver is a Radio Frequency Integrated Circuit (RFIC), having a substantially non-flat reception transfer function as a result of being an Integrated Circuit.

15. A Point-to-Point communication system, comprising:

a millimeter-wave channel having a substantially flat channel transfer function between a first frequency of millimeter-waves and a second frequency of millimeter-waves, the two frequencies are separated by at least 500 MHz;

a transmission system comprising an Orthogonal Frequency Division Multiplexing (OFDM) modulator configured to output an OFDM signal having a bandwidth of at least 100 MHz, and a radio transmitter having a transmission transfer function, configured to up-convert the OFDM signal into a millimeter-wave signal located between the first frequency and the second frequency, and to transmit the millimeter-wave signal via the millimeter-wave channel; and

a reception system comprising a radio receiver having a reception transfer function that in combination with the transmission transfer function of the radio transmitter results in a substantially non-flat radio transfer function denoting a difference of at least 6 dB between a highest magnitude and a lowest magnitude of a sum of frequency responses of the radio transmitter and the radio receiver over the bandwidth of the OFDM signal; the radio receiver configured to receive the millimeter-wave signal via the millimeter-wave channel and down-convert the millimeter-wave signal into a reconstruction of the OFDM signal having a bandwidth of at least 100 MHz, and an OFDM de-modulator configured to compensate for the substantially non-flat radio transfer function, by de-modulating the reconstruction of the OFDM signal.

16. The Point-to-Point communication system of claim 15 , wherein the millimeter-wave channel is a waveguide through which the millimeter-wave signal is transmitted, having the substantially flat channel transfer function between the first frequency and the second frequency.

17. The Point-to-Point communication system of claim 15 , wherein the substantially flat channel transfer function of the millimeter-wave channel is flat to a degree that does not require the use of an OFDM modulator and an OFDM de-modulator to facilitate communication over the millimeter-wave channel.

18. The Point-to-Point communication system of claim 17 , wherein the millimeter-wave channel is a wireless channel comprising a first directional antenna through which the millimeter-wave signal is transmitted, and a second directional antenna through which the millimeter-wave signal is received, and combined gain of the first directional antenna and the second directional antenna is at least 50 dBi, causing the millimeter-wave channel to have the substantially flat channel transfer function between the first frequency and the second frequency.

19. The Point-to-Point communication system of claim 18 , wherein the second millimeter wave frequency is between 50 GHz and 100 GHz.

20. The Point-to-Point communication system of claim 18 , wherein the OFDM signal having a bandwidth of at least 100 MHz is used to transmit data over the millimeter-wave channel at a rate of over 100 Mbps.

21. The Point-to-Point communication system of claim 15 , wherein the substantially flat channel transfer function is a transfer function having a difference of at most two dB between the highest magnitude and lowest magnitude of the transfer function in the range between the first frequency and the second frequency.

22. The Point-to-Point communication system of claim 21 , wherein the substantially non-flat radio transfer function is a transfer function having a difference of at least 6 dB between the highest magnitude and lowest magnitude of the transfer function in the range of the at least 100 MHz.

23. The Point-to-Point communication system of claim 15 , wherein the radio transmitter is a Radio Frequency Integrated Circuit (RFIC), and the radio receiver is a RFIC, resulting in a substantially non-flat radio transfer functions.

24. A Point-to-Point communication system, comprising:

a millimeter-wave channel having a substantially flat channel transfer function between a first frequency of millimeter-waves and a second frequency of millimeter-waves, the two frequencies are separated by at least 500 MHz;

a transmission system configured to transmit an Orthogonal Frequency Division Multiplexing (OFDM) signal having a bandwidth of at least 100 MHz over the millimeter-wave channel as a millimeter-wave signal located between the first frequency and the second frequency; and

a reception system comprising a radio receiver having a substantially non-flat reception transfer function denoting a difference of at least 4 dB between a highest magnitude and a lowest magnitude of a frequency response of the radio receiver over the bandwidth of the OFDM signal, the radio receiver configured to receive the millimeter-wave signal via the millimeter-wave channel and down-convert the millimeter-wave signal into a reconstruction of the OFDM signal having a bandwidth of at least 100 MHz, and an OFDM de-modulator configured to compensate for the substantially non-flat reception transfer function, by de-modulating the reconstruction of the OFDM signal.

25. The Point-to-Point communication system of claim 24 , wherein the millimeter-wave channel is a wireless channel comprising a first directional antenna through which the millimeter-wave signal is transmitted, and a second directional antenna through which the millimeter-wave signal is received, and combined gain of the first directional antenna and the second directional antenna is at least 50 dBi, causing the millimeter-wave channel to have the substantially flat channel transfer function between the first frequency and the second frequency.

26. The Point-to-Point communication system of claim 24 , wherein the millimeter-wave channel is a waveguide through which the millimeter-wave signal is transmitted, having the substantially flat channel transfer function between the first frequency and the second frequency.

27. The Point-to-Point communication system of claim 24 , wherein the substantially flat channel transfer function of the millimeter-wave channel is flat to a degree that does not require the use of an OFDM modulator and an OFDM de-modulator to facilitate communication over the millimeter-wave channel.

28. The Point-to-Point communication system of claim 27 , wherein the millimeter-wave channel is a wireless channel comprising a first directional antenna through which the millimeter-wave signal is transmitted, and a second directional antenna through which the millimeter-wave signal is received, and combined gain of the first directional antenna and the second directional antenna is at least 50 dBi, causing the millimeter-wave channel to have the substantially flat channel transfer function between the first frequency and the second frequency.

29. The Point-to-Point communication system of claim 28 , wherein the second millimeter wave frequency is between 50 GHz and 100 GHz.

30. The Point-to-Point communication system of claim 28 , wherein the OFDM signal having a bandwidth of at least 100 MHz is used to transmit data over the millimeter-wave channel at a rate of over 100 Mbps.

31. The Point-to-Point communication system of claim 24 , wherein the substantially flat channel transfer function is a transfer function having a difference of at most two dB between the highest magnitude and lowest magnitude of the transfer function in the range between the first frequency and the second frequency.

32. The Point-to-Point communication system of claim 31 , wherein the substantially non-flat reception transfer function is a transfer function having a difference of at least 4 dB between the highest magnitude and lowest magnitude of the transfer function in the range of the at least 100 MHz.

33. The Point-to-Point communication system of claim 24 , wherein the radio receiver is a Radio Frequency Integrated Circuit (RFIC), having a substantially non-flat reception transfer function as a result of being an Integrated Circuit.