Ultra-wideband high data-rate communication apparatus and associated methods

#This patent application relates generally to communication apparatus and, more particularly, to ultra-wideband (UWB) high data-rate (HDR) communication apparatus.

#The proliferation of wireless communication devices in unlicensed spectrum and the ever increasing consumer demands for higher data bandwidths has placed a severe strain on those frequency spectrum bands. Examples of the unlicensed bands include the 915 MHz, the 2.4 GHz Industrial, Scientific and Medical (ISM) band, and the 5 GHz Unlicensed National Information Infrastructure (UNII) bands. New devices and new standards emerge continually, for example, the IEEE 802.11b, IEEE 802.11a, IEEE 802.15.3, HiperLAN/2 standards. The emergence and acceptance of the standards has placed, and continues to place, a further burden on those frequency bands. Coexistence among the many systems competing for radio-frequency (RF) spectrum is taking on an increasing level of importance as consumer devices proliferate.

#Persons skilled in the art know that the available bandwidth of the license-free bands (and the RF spectrum available generally) constrains the available data bandwidth of wireless systems. Furthermore, data-rate throughput capability varies proportionally with available bandwidth, but only logarithmically with the available signal-to-noise ratio. Hence, to transmit increasingly higher data rates within a constrained bandwidth requires the use of complex communication systems with sophisticated signal modulation schemes.

#The appended drawings illustrate only exemplary embodiments of the invention and therefore should not be considered as limiting its scope. The disclosed inventive concepts lend themselves to other equally effective embodiments. In the drawings, the same numeral designators used in more than one drawing denote the same, similar, or equivalent functionality, components, or blocks.

#FIG. 1 shows several power spectral density (PSD) profiles in various embodiments according to the invention.

#FIG. 2 illustrates exemplary signal waveforms corresponding to a high data-rate UWB apparatus.

#This invention contemplates high data-rate communication apparatus and associated methods. Communication apparatus according to the invention provide a solution to the problems of coexisting communication systems, and yet providing relatively high data-rates. Note that wireless or radio communication systems according to the invention provide relatively high data-rates in “hostile” propagation environments, such as multipath environments. Furthermore, as described below, one may apply the inventive concepts described here to land-line communication systems, for example, communication systems using coaxial cables, or the like.

#In one exemplary embodiment according to the invention, a high data-rate UWB data transmission system uses a binary phase shift keying (BPSK) modulation of a carrier frequency, known to persons of ordinary skill in the art with the benefit of the description of the invention. One obtains the power spectral density (PSD) at frequency ƒ of such a system as: 1 P n = 2 ⁢ n ⁢ ⁢ f c 2 π · [LeftBracketingBar] sin ⁡ ( π ⁢ ⁢ f f c ) f 2 - ( n ⁢ ⁢ f c ) 2 [RightBracketingBar] 2 ,

#where ƒc denotes the reference clock frequency, and n represents the number of carrier cycles per chip. In other words, 2 n = # ⁢ ⁢ of ⁢ ⁢ carrier ⁢ ⁢ cyles 1 ⁢ ⁢ chip .