# US 6,532,256 B2 · Method and apparatus for signal transmission and reception > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,532,256 B2 - Document ID: US6532256B2 - Status: Granted - Kind: B2 - Application number: 09/894,168 - Filed: 2001-06-27 - Published: 2002-01-24 - Granted: 2003-03-11 - Earliest claimed: 1993-03-17 - Assignees: Rainmaker Technologies, Inc. - Inventors: William J. Miller - Web page: https://patentgrep.com/patent/US6532256B2 ## CPC - H04K 1/02: by adding a second signal to make the desired signal unintelligible - H04L 25/03343: {Arrangements at the transmitter end} - H04L 69/40: for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) - H04K: SECRET COMMUNICATION; JAMMING OF COMMUNICATION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Serial input data is partitioned into parallel data elements prior to rotation by an invertible linear mapping. The resulting frames of parallel signal elements are sequentially transmitted over the link. After receipt from the link, the signal is demodulated and assembled into frames of parallel signal elements which are de-rotated by an inverse linear mapping. The recovered parallel data elements are then re-assembled into serial output data. The linear mapping employs: 1) commuting rotation matrices for convolutionally rotating data vectors into signal vectors and vice-versa; 2) filter bank polyphase rotation matrices; or 3) computationally efficient multi-rate wavelet filter banks. Coefficients of the rotation matrix of the receiver are adaptively equalized to correct for transmission path distortion. A test signal may be inserted on the transmit side for receiver synchronization or link distortion characterization. ## Claims ### Claim 1 A communications system, comprising: a rotation element for wavelet synthesizing a parallel data set into a serialized signal; a test signal generator for generating a test signal component within said serialized signal; and a transmitter element, in communication with said rotation element, for transmitting said serialized signal over a transmission link. ### Claim 2 (depends on 1) The communications system of claim 1, further comprising a partitioning element for dividing serial input data into said parallel data set on a plurality of respective channels. ### Claim 3 (depends on 2) The communications system of claim 2, wherein said partitioning element comprises a sampling clock circuit for timing the division of said serial input data and wherein said test signal component from said test signal generator is synced to said sampling clock circuit. ### Claim 4 (depends on 2) The communications system of claim 2, wherein said partitioning element comprises a clock circuit for timing the division of said serial input data at a per-frame rate and wherein said test signal component from said test signal generator is provided having a sign alternating at said per-frame rate. ### Claim 5 (depends on 2) The communications system of claim 2, wherein said test signal generator is in communication with said rotation element and wherein said test signal generator generates said test signal component on at least one of said plurality of channels. ### Claim 6 (depends on 1) The communications system of claim 1, wherein said rotation element comprises a modulator for modulating a carrier with said parallel data set in realizing said serialized signal. ### Claim 7 (depends on 1) The communications system of claim 1, wherein said test signal generator comprises a timing circuit for generating a clock signal as said test signal component within said serialized signal. ### Claim 8 (depends on 7) The communications system of claim 7, further comprising an adder circuit in communication with said test signal generator and said rotation element for adding said clock signal from said timing circuit to said serialized signal from said rotation element. ### Claim 9 (depends on 7) The communications system of claim 7, wherein said test signal generator is in communication with said rotation element and said clock signal is provided as an input to said rotation element along with said parallel data set. ### Claim 10 (depends on 1) The communications system of claim 1, wherein said test signal generator is in communication with said rotation element, wherein said test signal component is provided as a repeating data pattern, and wherein said test signal component is provided as an input to said rotation element along with said parallel data set. ### Claim 11 (depends on 10) The communications system of claim 10, wherein said repeating data pattern is a non-varying data stream. ### Claim 12 (depends on 10) The communications system of claim 10, wherein said test signal component is provided to at least one subband of said rotation element. ### Claim 13 (depends on 1) The communications system of claim 1, wherein said test signal generator is for generating said test signal component as a correlating data sequence, wherein said test signal generator is in communication with said rotation element, and wherein said test signal component is provided as an input to said rotation element along with said parallel data set. ### Claim 14 (depends on 1) The communications system of claim 1, wherein said test signal generator is realized by said rotation element operating on a null parallel data set. ### Claim 15 (depends on 1) The communications system of claim 1, further comprising an encryptor in communication with said rotation element. ### Claim 16 (depends on 15) The communications system of claim 15, wherein said encryptor is provided as a broadband random number generator. ### Claim 17 (depends on 16) The communications system of claim 16, wherein said test signal generator is realized by said encryptor with said rotation element operating on a null parallel data set. ### Claim 18 (depends on 1) The communications system of claim 1, wherein said rotation element is comprised of a plurality of frequency subbands, said test signal generator is for interjecting an isolated test data set into said parallel data set applied to said plurality of frequency subbands. ### Claim 19 (depends on 18) The communications system of claim 18, wherein said isolated test data set comprises a first temporal period of null data symbols on all of said rotation element subbands, a second temporal period of test symbols on first ones of said rotation element subbands, a third temporal period of null data symbols on all rotation element subbands, a fourth temporal period of test symbols on second ones of said rotation element subbands, and a fifth temporal period of null data symbols on all rotation element subbands. ### Claim 20 (depends on 19) The communications system of claim 19, wherein said first and second ones of said rotation element subbands are mutually exclusive. ### Claim 21 (depends on 19) The communications system of claim 19, wherein each of said first and second ones of said rotation element subbands are non-contiguous in frequency. ### Claim 22 A data communications system for receiving a serialized signal and for substantially recovering an original parallel data set from which said serialized signal is generated, comprising: a receiver element for receiving said serialized signal including a test signal component from a transmitter element via a transmission link; an inverse rotation element, in communication with said receiver element, for receiving said serialized signal from said receiver element and for wavelet analyzing said serialized signal into a recovered parallel data set; and a test signal extraction element for extracting said test signal component from said received, serialized signal, wherein said wavelet analysis is the inverse of a wavelet synthesis applied to said original parallel data set in generating said serialized signal. ### Claim 23 (depends on 22) The data communications system of claim 22, further comprising an assembly element, in communication with said inverse rotation element, for receiving and assembling said recovered parallel data set into serial output data. ### Claim 24 (depends on 22) The data communications system of claim 22, wherein said inverse rotation element comprises a demodulator for demodulating said serialized signal from a carrier. ### Claim 25 (depends on 22) The data communications system of claim 22, wherein said test signal extraction element is adapted for extracting said test signal component as a narrow-band tone of fixed frequency. ### Claim 26 (depends on 25) The data communications system of claim 25, further comprising a receiver oscillator in communication with said test signal extraction element and said inverse rotation element, wherein said test signal extraction element is further for synchronizing said receiver oscillator to said extracted test signal component. ### Claim 27 (depends on 26) The data communications system of claim 26, wherein an output from said receiver oscillator is provided as a clock input to said inverse rotation element. ### Claim 28 (depends on 26) The data communications system of claim 26, wherein said test signal extraction element comprises a cancellation circuit for extracting said test signal component form said received, serialized signal by cancellation. ### Claim 29 (depends on 26) The data communications system of claim 26, wherein said test signal extraction element comprises a feedback loop for extracting said test signal component from said received, serialized signal using said feedback loop and for synchronizing said receiver oscillator to said extracted test signal component. ### Claim 30 (depends on 26) The data communications system of claim 26, wherein said test signal extraction element is adapted for using transitions in the sign of said extracted test signal component to synchronize said inverse rotation element to said extracted test signal component. ### Claim 31 (depends on 22) The data communications system of claim 22, wherein the amplitude of said extracted test signal component corresponds to a power level associated with said serialized signal, whereby said receiver element compensates for said power level based upon said amplitude of said test signal component. ### Claim 32 (depends on 22) The data communications system of claim 22, wherein said test signal extraction element is in communication with said inverse rotation element for extracting said test signal component as a correlating sequence from said serialized signal. ### Claim 33 (depends on 22) The data communications system of claim 22, wherein said test signal extraction element is in communication with said inverse rotation element, said test signal extraction element is adapted for receiving said test signal component on a channel of said inverse rotation element, and said test signal extraction element is adapted for comparing said test signal component with a predetermined value to assess the response of the respective channel. ### Claim 34 (depends on 33) The data communications system of claim 33, wherein said response assessed by said test signal extraction element is characteristic of a metric selected from the group consisting of phase shift, power loss, and relative delay. ### Claim 35 (depends on 22) The data communications system of claim 22, wherein said test signal extraction element is in communication with said inverse rotation element, said test signal extraction element is adapted for receiving a respective portion of said test signal component on each channel of said inverse rotation element, and said test signal extraction element is adapted for comparing each portion of said test signal component with each other portion of said test signal component to assess the relative response of each channel. ### Claim 36 A communications system, comprising: a rotation element for wavelet synthesizing an original parallel data set into a serialized signal; a test signal generator for generating a test signal component within said serialized signal; a transmitter element, in communication with said rotation element, for transmitting said serialized signal over a transmission link; a receiver element for receiving said serialized signal including a test signal component from said transmitter element via said transmission link; an inverse rotation element, in communication with said receiver element, for receiving said serialized signal from said receiver element and for wavelet analyzing said serialized signal into a recovered parallel data set; and a test signal extraction element for extracting said test signal component from said received, serialized signal, wherein said wavelet analysis is the inverse of said wavelet synthesis applied to said original parallel data set in generating said serialized signal.