公开(公告)号：EP0865687A4

公开(公告)日：2003-05-28

申请号：EP96943509

申请日：1996-11-15

申请人： AXONN L L C

发明人： SANDERFORD H BRITTON ,  ROUQUETTE ROBERT E ,  NADEN GARY A

IPC分类号： H04B1/707

CPC分类号： H04B1/70752 ,  H04B1/707 ,  H04B1/70755 ,  H04B1/70775 ,  H04B1/708 ,  H04B1/7097 ,  H04B1/7101

摘要： A direct sequence spread spectrum (DSSP) DSP implementation technique utilizing a unique combination of multiple filters (DSP Channel Fltr), transforms, despreading algorithm and spectral compression, all in a single coefficient set, providing a highly efficient system. Reallocatable computational resources allow for frequency uncertainty in the transmitter, without the typical excessive noise bandwidth penalties. The present system further contemplates a unique energy detection algorithm for discerning spread spectrum while in the search mode, utilizing discrete sampling data sets to increase signal strength, reducing noise, while changing the relative phase of the received chipping code with respect to the received signal. The spectral compression of the spreading sequence is achieved by representing the PRC as an array of two, complementing fractional coefficients. The PRC code is filtered to achieve the required spectral compression characteristics, resulting in minimal despreading loss, while providing interference rejection of CW signals greater than 1.5 MHz from the center IF frequency.

公开(公告)号：EP0986860A4

公开(公告)日：2003-05-02

申请号：EP98937930

申请日：1998-05-18

申请人： AXONN L L C

发明人： SANDERFORD BRITTON H JR ,  NADEN GARY A ,  ROUQUETTE ROBERT E ,  REISER DALE E ,  HWANG CHARLES A ,  REED MARC L

IPC分类号： H04B1/69 ,  H04B1/707

CPC分类号： H04B1/707

摘要： A system employs a digital receiver (or transceiver) to receive, digitize and process a direct sequence spread spectrum signal using digital signal processing components. A radio front end portion of the receiver receives and digitizes the signal, and a digital signal processing portion downconverts and despreads the signal by applying a pseudorandom noise (PN) code, used at a transmitter to spread a data signal contained in the direct sequence spread spectrum signal, to the received signal. A timing and state control mechanism is included to provide time reference correction information to the signal processing components of the receiver for alignment of the PN code with the direct sequence spread spectrum signal, allowing the receiver to be compatible with transmitters using inaccurate frequency references which impart a significant frequency ambiguity in the received signal. Computer-based synchronization methods and mechanisms suitable for use for low performance digital signal processors, and power management mechanisms are employed to enable long-term operations using battery power, enabling utilization in network settings.

公开(公告)号：EP0872016A4

公开(公告)日：2003-04-23

申请号：EP96930486

申请日：1996-06-06

申请人： AXONN L L C

发明人： SANDERFORD H BRITTON JR ,  ROUQUETTE ROBERT E ,  DAVIS ROBERT J

IPC分类号： H04B1/707 ,  H04B1/7075 ,  H04B1/7077 ,  H04B1/708 ,  H04B1/7097 ,  H04B1/71 ,  H04B1/74 ,  H04J13/04 ,  H04L7/10 ,  H04L27/06

CPC分类号： H04B1/70752 ,  H04B1/707 ,  H04B1/70755 ,  H04B1/70775 ,  H04B1/708 ,  H04B1/7097 ,  H04B1/7101

摘要： A parallel frequency acquisition technique is disclosed for increasing receiver sensitivity and increasing process gain while reducing the necessary preamble duration required for spread spectrum acquisition. In addition, techniques are disclosed for reducing the effects of jamming and impulse noise on the performance of the receiver as well as enhanced antenna diversity approaches. Further, techniques are taught which compensate for chip code alignment drift, providing an associated transmitter maintains carrier and chip code coherence. These techniques allow for the use of lower cost frequency setting crystals in both the receiver and transmitter as well as the operation of the system over a wider temperature range.

摘要翻译： 公开了一种并行频率获取技术，用于增加接收器灵敏度并增加过程增益，同时减少扩频采集所需的前导码持续时间。 另外，公开了用于降低干扰和脉冲噪声对接收机性能的影响以及增强的天线分集方法的技术。 此外，教授了补偿码片对准漂移的技术，提供了相关联的发射器，以维持载波和码片的一致性。 这些技术允许在接收器和发射器中使用较低成本的频率设定晶体以及在较宽温度范围内操作系统。

公开(公告)号：EP1114532A4

公开(公告)日：2003-06-04

申请号：EP99938699

申请日：1999-07-14

申请人： AXONN L L C

发明人： ROUQUETTE ROBERT E

IPC分类号： H04B1/10 ,  H04B1/707 ,  H04B15/00 ,  H04K1/00 ,  H04L7/00 ,  H04L27/30

CPC分类号： H04B1/7102 ,  H04B1/1036

摘要： A spread spectrum receiver and method having narrow-band interference rejection of narrow-band jamming signals using digital signal processing frequency domain techniques. The method performed in the receiver includes transforming the received signal to a frequency domain signal and identifying narrow-band interference components in the frequency domain signal; suppressing the identified narrow-band interference components by excising the identified narrow-band interference components from the frequency domain signal to produce an interference excised signal in the frequency domain, and storing in a memory frequencies corresponding to the identified narrow-band interference components; synchronizing a receiver code to a transmitter code in the frequency domain using the interference excised signal; generating coefficients for a time domain filter that includes notches at the frequencies corresponding to the excised narrow-band interference components and that jointly despreads and rejects narrow-band interference from the excised frequencies; applying the coefficients generated in the preceding step to the time domain filter; and despreading and filtering in real time in the time domain the received signal using the applied coefficients.