Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2002-07-23
2004-06-01
Tokar, Michael J. (Department: 2819)
Pulse or digital communications
Receivers
Interference or noise reduction
C455S012100, C455S013300, C455S226200
Reexamination Certificate
active
06744832
ABSTRACT:
BACKGROUND
This invention relates generally to ultra wideband communications.
Ultra wideband communications (UWB) is true digital radio communication; completely unlike the radios we listen to and communicate every day. UWB is a wireless broadband communications technology fundamentally different from all other radio frequency (RF) communications. UWB achieves wireless broadband communication without using a RF carrier. Instead, UWB is a sequence of very short electrical pulses, billionths of a second long, which exist not on any particular frequency but on all frequencies simultaneously. UWB uses modulated pulses with less one nanosecond in duration. The modulated pulse is usually assigned a digital representation of 0 or 1 to the transmitted and received pulse based on where the pulse is place in time. The key to turning the digital pulses into wireless broadband communication lies in the timing of the pulses. In order to hear the information in that code, a UWB receiver has to know the exact pulse sequence used by the transmitter.
Each pulse can exist simultaneously across an extensive band of frequencies if the distributed energy of the pulse at any given frequency exists in the noise floor. Therefore, UWB can co-exist with RF carrier-based communications with no discernable interference. This opens vast new communications with providing tremendous wireless bandwidth to ease the growing bandwidth crunch.
The U.S. Federal Communications Commission (FCC) on Feb. 14, 2002 authorized limited commercial use of wireless devices based on a communication technology called ultra wideband. The FCC's restrictions require that commercial ultra wideband devices must operate in radio spectrum in the frequency ranges from 3.1 GHz to 10.6 GHz. UWB communication devices should also satisfy by Part 15.209 rule, which set emission limits for operation.
UWB communication transceivers can transfer information data at rates of 100 mega-bit per second (Mbps) to 1 giga-bit per second (Gbps), with sending repeated ultra-short pulse signals across distances as great as 500 feet, even up to 2 kilometers.
With transmitting repeated ultra-short pulse signals for the high data rate up to 1 Gbps in the frequency ranges from 3.1 to 10.6 GHz, an analog-to-digital (A/D) converter should operate at very high sampling rate F
s
so that UWB communication receiver can implement in a digital domain. Usually, the sampling rate F
s
must be greater than two-time the highest frequency F
max
in the ultra-short pulse signals. This may lead to have a difficult problem to design an A/D converter with such high-speed operation in an UWB communication transceiver.
In addition, digital down conversion (DDC) should shift the bandpass ultra-shout pulse signals of the output of the A/D converter into the baseband signals and perform the decimation of the baseband signals with high sampling rate into low sampling rate due to the repeated pulse signals during transmitting.
Thus, there is a continuing need for an A/D converter bank with operating at a lower-speed to substitute a very-high-speed A/D converter along with a digital down conversion for a digital UWB communication transceiver.
SUMMARY
In accordance with one aspect, an A/D converter bank based UWB receiver comprises a low noise amplifier (LNA) coupled to an anti-aliasing analog filter, an A/D converter bank with a sampling frequency rate of F
s
, a digital down conversion coupled to a rake receiver and a channel estimate, a template pulse generator coupled to the rake receiver to calculate a correlation between a received monocycle pulse and an ideal monocycle pulse, a sequence generator coupled to the template pulse generator, a synchronization coupled to the template pulse generator, and a clock control coupled to the A/D converter bank, the digital down conversion and the template pulse generator.
Other aspects are set forth in the accompanying detailed description and claims.
REFERENCES:
patent: 5280636 (1994-01-01), Kelley et al.
patent: 5404375 (1995-04-01), Kroeger et al.
patent: 5640698 (1997-06-01), Shen et al.
patent: 5745846 (1998-04-01), Myer et al.
patent: 5956620 (1999-09-01), Lazaris-Brunner et al.
patent: 6101399 (2000-08-01), Raleigh et al.
patent: 6167099 (2000-12-01), Rader et al.
patent: 6301465 (2001-10-01), Kintis et al.
patent: 6363262 (2002-03-01), McNicol
patent: 2003/0021367 (2003-01-01), Smith
Nguyen Linh V
Tokar Michael J.
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