System and apparatus for high data rate wireless communications

• US 8,527,003 B2
• Filed: 05/09/2007
• Issued: 09/03/2013
• Est. Priority Date: 11/10/2004
• Status: Expired due to Fees

• Current Assignee: Spero Devices, Inc.
• Original Assignee: Newlans, Inc. (Royal KPN NV)
• Inventors: Gupta, Dev V., Wood, Kenneth, Mathew, Abbie
• Primary Examiner(s): Zewdu, Meless N
• Assistant Examiner(s): Nguyen, Michael
• Application Number:
  US11/801,421
• Publication Number:
  US 20080002652A1
• Time in Patent Office: 2,309 Days
• Field of Search: 455557-559
• US Class Current: 455/557
• CPC Class Codes: H01Q 1/2291 used in bluetooth or WI-FI devices of Wireless Local Area Networks [WLAN] H01Q1/241 takes precedence; WLAN in general H04W
• CPC Class Codes: H01Q 13/0241 radiating a circularly polarised wave H01Q13/0258 takes precedence; polarisation converters H01Q15/244, in a waveguide H01P1/17
• CPC Class Codes: H01Q 15/244 converting a linear polarised wave into a circular polarised wave guided wave H01P1/17
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave
• CPC Class Codes: H04L 25/03834 using pulse shaping

Abstract

A system and apparatus including a wireless network architecture that provides broadband data network coverage over an expandable geographic area. A media access control layer is also provided that facilitates access to the broadband wireless network. A high-frequency wireless modem enables high data rate access to the wireless network in a spectrally-efficient manner using SSB modulation. A wideband millimeter-wave antenna includes a cosecant-squared reflector enabling signal propagation between network elements thereby enabling seamless wireless communications. A millimeter-wave polarizer, and a septum polarizer each convert between linear and circular polarization. A cross-shaped horn antenna adapted for circularly polarized signals can also be used in combination with the septum polarizer. A combined horn antenna is fed using a microstrip patch antenna.

Claims

1. A digital communications modem that uses analog signal processing to transform an information signal into a combined encoded signal, the modem comprising:

a pulse-shaping filter receiving the information signal having a baud rate and generating a filtered pulse train having a reduced bandwidth that is less than the baud rate;

an encoder receiving the filtered pulse train and generating an encoded signal having one of two orthogonal relationships;

a combiner receiving two encoded signals having different orthogonal relationships and combining them, the resulting combined encoded signal having a signal bandwidth within the reduced bandwidth.

2. The digital communications modem of claim 1, further comprising a modulator modulating a carrier signal with the combined encoded signal, the modulated signal having a signal spectrum within a bandwidth of less than half of the baud rate of the received information signal.

3. The digital communications modem of claim 2, further comprising a frequency translator receiving the modulated signal at a first frequency band and translating it to a different frequency band.

4. The digital communications modem of claim 3, wherein the frequency translator translates the encoded information signal to a millimeter-wave frequency band.

5. The digital communications modem of claim 4, wherein the millimeter-wave frequency band is between about 30 GHz and about 300 GHz.

6. The digital communications modem of claim 4, wherein the millimeter-wave frequency band is between about 50 GHz and about 70 GHz.

7. The digital communications modem of claim 1, wherein the pulse-shaping filter comprises a raised cosine filter.

8. The digital communications modem of claim 1, wherein the pulse-shaping filter comprises a part of a matched filter, the other part of the matched filter provided within a remote receiver.

9. The digital communications modem of claim 1, wherein the encoder comprises a dual-rail binary encoder.

10. The digital communications modem of claim 9, wherein the dual-rail binary encoder comprises a Hilbert Transformer.

11. The digital communications modem of claim 2, wherein the modulator comprises a sideband suppressor suppressing one of two sidebands of the modulated signal.

12. The digital communications modem of claim 11, wherein the sideband suppressor comprises a filter.

13. The digital communications modem of claim 2, wherein the modulator comprises a single side band (SSB) modulator.

14. The digital communications modem of claim 2, wherein the modulator comprises a vestigial side band (VSB) modulator.

15. The digital communications modem of claim 1, further comprising a first pilot signal source combining a first pilot signal with the filtered pulse train, the first pilot signal having a center frequency of about half the baud rate.

16. The digital communications modem of claim 15, further comprising a second pilot signal source combining a second pilot signal with the filtered pulse train, the second pilot signal having a center frequency corresponding to the inverse of twice the baud period at baseband.

17. The digital communications modem of claim 16, wherein the second pilot signal is provided with a well-defined power level.

18. The digital communications modem of claim 1, further comprising a millimeter-wave wireless transmitter, the transmitter transmitting the combined encoded signal wirelessly at a carrier frequency greater than about 30 GHz.