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The present invention generally relates to multi-access communications by code division CDMA: Code Division Multiple Accessalso known as communications from extended spectrum More particularly, the present invention is refers to a system and a method to provide a system of Code Division Multiple Access Communications CDMA of large capacity that handles one or more carrier channels simultaneous users of a given radio frequency, allowing the dynamic allocation of carrier channel frequency while rejects multipath interference.
Proporcionar servicios de telecomunicación de calidad a grupos de usuarios que son clasificados como remotos, tales como sistemas telefónicas rurales y sistemas telefónicos en países subdesarrollados, ha demostrado ser what are the different levels of the linnaean classification system desafío en años recientes. Usually these remote services are faced with more potential users that those that can be supported simultaneously for their ability frequency bandwidth or spectral.
La modulación de espectro extendido se refiere a modular una señal de información con una señal de código de extensión, siendo la señal de código de extensión generada por una generador de código donde el período Tc del código de extensión es sustancialmente menor que el período de la señal de símbolos o bits de datos de información. El código puede modular la frecuencia de portadora en la que se ha enviado la información, denominado extensión de salto de frecuencia, o puede modular directamente la señal multiplicando el código de extensión por la señal de datos de información, denominado extensión de secuencia directa.
La modulación de espectro extendido produce una señal con anchura de banda sustancialmente mayor que la requerida para transmitir la señal de información. La recepción sincrónica y la contracción de la señal en el receptor recuperan la información original. Un desmodulador sincrónico en el receptor usa una señal de referencia para sincronizar los circuitos de contracción con la señal modulada de espectro extendido para recuperar las señales de portadora e información.
La señal de referencia puede ser un código de extensión que no es modulado por una señal de información. Recognizing these limitations, advances Recent wireless communications have used extended spectrum modulation to provide communication simultaneous by multiple users. Spectrum modulation Extended refers to modulating an information signal with a extension code signal, the code signal being extension generated by a code generator where the Tc period of the extension code is substantially less than the period of the signal of symbols or bits of information data.
The code can modulate the carrier frequency at which the information, called frequency hopping extension, or it can directly modulate the signal by multiplying the extension code by the information data signal, called extension of direct sequence Extended spectrum modulation produces a signal with bandwidth substantially greater than required to transmit the information signal.
The synchronous reception and the contraction of the signal in the receiver retrieves the information original. A synchronous demodulator in the receiver uses a signal from reference to synchronize the contraction circuits with the extended spectrum modulated signal to recover signals from believing that association is the same as causation and information.
The reference signal can be a code extension the transitive closure of a relation r on set a whose relation matrix is not modulated by an information signal. La modulación de espectro extendido también reduce los efectos debidos a otras fuentes de interferencia. Extended spectrum modulation in networks Wireless offers many advantages because multiple users can use the same frequency band with minimal interference in each user receiver Extended the transitive closure of a relation r on set a whose relation matrix modulation also reduces the effects due to other sources of interference.
In addition, synchronous modulation and demodulation techniques of Extended spectrum can be extended by providing channels of multiple messages for a single user, each extended with a different extension code, while still transmitting only a unique reference signal to the user. Estos sistemas emplean una familia de códigos de extensión ortogonales o casi ortogonales, con una secuencia de código de extensión piloto sincronizada con la familia de códigos. Cada usuario tiene asignado uno de los códigos de extensión como una función de extensión.
An area where spectrum techniques are used extended is in the field of mobile cellular communications to provide personal communications services PCS. Such systems what is the definition of abusive relationship support large numbers of users, control displacement and doppler fading and provide high-speed digital data signals with rates Small bit errors. These systems employ a family of orthogonal or almost orthogonal extension codes, with a pilot extension code sequence synchronized with the family of codes.
Each user is assigned one of the codes of Extension as an extension function. Related Issues of Such a system are: support a large number of users with codes orthogonal, handle the reduced power available for remote units and handle fading effects by multiple paths. Solutions to such problems include using multiple antennas with elements in phase to generate beams Multiple orientable, use very long code sequences orthogonal or almost orthogonal.
These sequences can be reused by cyclic scrolling of the synchronized code with a central reference, and combination in signal diversity multi-path. Los problemas asociados con los sistemas de técnica anterior se enfocan alrededor de la recepción fiable y la sincronización de los circuitos contractivos del receptor con la señal recibida.
Tal receptor es descrito, por ejemplo, en la Patente de EE. The problems associated with the systems of prior art focus around reliable reception and synchronization of the receiver's contracting circuits with the received signal The presence of fade paths multiple introduces a particular problem with the receivers of extended spectrum because a receiver must somehow track multipath components to maintain the hitch of phase code of the contractual means of the receiver with the signal input Prior art receivers track generally only one or two of the multipath signals, but this method is not satisfactory because the combined group of low power multipath signal components it can really contain much more power than one or both stronger multipath components.
Recipients of prior art track and combine the strongest components to maintain a default BER bit error rate of Receiver Such a receiver is described, for example, in the Patent of USA 5, entitled "Receiver in diversity in a system multi-access cell phone by code division Gilhousen and others. A receiver that combines all the components of multipath, however, is able to maintain the rate desired bit errors with a signal strength that is lower the transitive closure of a relation r on set a whose relation matrix that of prior art systems because more power of Signal is available to the receiver.
Therefore, there is a need for an extended spectrum communication system that employ a receiver that tracks substantially all components of multipath signals, so that substantially all multipath signals can be combined in the transitive closure of a relation r on set a whose relation matrix receiver and therefore the power of required signal transmission for a bit error rate BER given.
Otra sincronización del estado de la técnica se describe en el documento "Diseño de un receptor todo digital para banda estrecha de fase continua asíncrona en sistemas CDMA" por Giannetti et al. Another synchronization of the state of the art is described in the document "Design of an all digital receiver for asynchronous continuous phase narrowband in CDMA systems" by Giannetti et al. Por consiguiente, los usuarios que transmiten con niveles altos de potencia de señal pueden interferir con la recepción de otros usuarios.
Al mismo tiempo, el sistema debería mantener relativamente constante la potencia que la estación base recibe de todos los usuarios. Another problem associated with extended spectrum communication systems, multiple access is the need to reduce the total transmitted power of users in the system since users may have limited available power. An associated problem that requires power control in extended spectrum systems is related to the inherent feature of extended spectrum systems that a user's extended spectrum signal is received by another user's receiver as noise with a certain level of power.
Therefore, users who transmit with high levels of signal power may interfere with the reception of other users. Also, if a user why does my phone no longer go to voicemail with respect to the geographical position of another user, fading and signal distortion require users to adjust their transmission power level to maintain a particular signal quality. At the same time, the system should keep the power that the base station receives from all users relatively constant.
Finally, since it is possible that the extended spectrum system has more remote users than can be simultaneously supported, the power control system should also employ a capacity management method that rejects additional users when the maximum power level is reached. Los sistemas de espectro extendido anteriores han empleado una estación base que mide una señal recibida y envía una señal de control adaptable de potencia APC: adaptive power control a los usuarios remotos.
En tales sistemas, la estación base supervisa la potencia global del sistema o la potencia recibida de cada usuario, y dispone consiguientemente la señal de control adaptable de potencia APC. Este comportamiento funcional del sistema en bucle abierto puede ser mejorado incluyendo una medición de la potencia de señal recibida por el usuario remoto desde la estación base y transmitiendo una señal APC de vuelta a la estación base para efectuar un método de control de potencia en bucle cerrado.
Previous extended spectrum systems have employed a base station that measures a received signal and sends a adaptive power control signal APC: adaptive power control to remote users. Remote users include a transmitter with an automatic gain control AGC circuit which responds to the adaptive power control signal APC. In such systems, the base station monitors the overall power of the system or power received from each user, and has consequently the adaptive power control signal APC.
This functional behavior of the open loop system can be enhanced including a measurement of the received signal power by the remote user from the base station and transmitting a APC signal back to the base station to perform a method of closed loop power control. Sin embargo, estos sistemas de control de potencia presentan varias desventajas. Primera, la estación base debe realizar algoritmos complejos de control de potencia, incrementando la cantidad de procesamiento en la estación base.
Estas variaciones ocurren con frecuencia diferente, así los algoritmos sencillos de control de potencia pueden ser optimizados para what is the scientific definition of causation sólo uno de los dos tipos de variación. Finalmente, estos algoritmos de potencia tienden a llevar la potencia total del sistema a un nivel relativamente alto. Asimismo, existen una necesidad de un sistema perfeccionado de comunicación de espectro extendido que emplee un sistema de control de potencia en bucle cerrado que haga mínimas las exigencias de potencia total del sistema mientras mantiene una tasa suficiente de errores de bits en los receptores remotos individuales.
However, these control the transitive closure of a relation r on set a whose relation matrix of Power present several disadvantages. First, the base station must perform complex power control algorithms, increasing the amount of processing at the base station. Second, the system really experiences several types of variation power: variation in the noise power caused by the variation in the number of users and variations in the power of signal received from a particular carrier channel.
These variations occur with different frequency, so the simple algorithms of Power control can be optimized to compensate for only one of the two types of variation. Finally, these algorithms of power tend to bring the total system power to a level relatively high Therefore, there is a need for a method Extended spectrum power control that responds quickly to changes in channel power levels carriers while simultaneously making power adjustments of transmission of all users in response to changes in the Number of users.
There is also a need for a system. In addition, such a system should control the level Initial transmission power of a remote user and manage Total system capacity. Spectrum communication systems extended should desirably withstand large numbers of users, each of which has at least one channel of communication. In addition, such a system should provide channels Multiple generic information to disseminate information to all users and allow users to access the system.
Using prior art extended spectrum systems, this could only be achieved by generating large numbers of sequences of extension codes. Sin embargo, es difícil generar tales familias grandes de secuencias de códigos. Asimismo, generar grandes familias de códigos requiere generar secuencias que tienen un período largo antes de la repetición. Por consiguiente, se incrementa el tiempo que requiere un receptor para conseguir la sincronización con tal secuencia larga.
Por tanto, existe una necesidad de un método perfeccionado para generar fiablemente grandes familias de secuencia de códigos que exhiban características casi ortogonales y tengan un período largo antes de la repetición, pero también incluyan el beneficio de una secuencia corta de código que reduzca el tiempo para adquirir y enganchar el receptor con la fase correcta de código. In addition, extended spectrum systems they should use sequences that are orthogonal or almost orthogonal to reduce the likelihood of a receiver engaging with the wrong phase or sequence of extension code.
However it is difficult to generate such large families of code sequences. Likewise, generating large families of are sweet potato fries healthier than potato fries requires generating sequences that have a long period before repetition. By consequently, the time required for a receiver to increase get synchronization with such a long sequence. The prior art extension code generators combine frequently shorter sequences to form more sequences long, but such sequences may no longer be sufficiently orthogonal Therefore, there is a need for a method perfected to reliably generate large sequence families of codes that exhibit almost orthogonal characteristics and have a long period before repetition, but also include the benefit of a short sequence of code that reduces time to acquire and hook the the transitive closure of a relation r on set a whose relation matrix with the correct phase of code.
In addition, the code the transitive closure of a relation r on set a whose relation matrix method should allow code generation with any period, since the Extension code period is frequently determined how do i respond to someone calling me pretty the parameters used such as the frequency of data or what traits does ancestry dna test for size of plot.
Por consiguiente, el sistema de comunicación de espectro extendido también debería generar secuencias de códigos de extensión de longitud par. Another desirable feature of the sequences of extension codes is that the data value transition from user occurs in a transition of the sequence values of code, as the data typically have a period that is divisible by 2 N, such a feature usually requires that the code sequence has an even length of 2 N. Without However, code generators, as is well known in the technique, they generally use linear displacement registers with feedback that generate length codes 2 N Therefore, the system of extended spectrum communication should also generate even length extension code sequences.
Finally, the communication system of extended spectrum should be able to handle many types different data, such as FAX facsimileband data Voice and Integrated Services Digital Network ISDNin addition to traffic Traditional voice To increase the number of supported users, Many systems employ communication techniques, such as adaptive differential pulse coding modulation ADPCMto achieve "compression" of the telephone signal.
Therefore, there is a need for a system of Extended spectrum communication that supports technical compression that also dynamically modify the carrier channel of extended spectrum between an encoded channel and a channel without encode in response to the type of information contained in the signal of user. La presente invención se refiere a una unidad de abonado como se reivindica en la reivindicación 1.
The present invention relates to a unit of subscriber as claimed in claim 1. Figure 1 is a block diagram of a multiple access communication system by division of code. La Figura 2a es un esquema de bloques de un registro lineal de desplazamiento de 36 etapas adecuado para uso con código de extensión largo del generador de códigos. Figure 2a is a block diagram of a stage linear shift register suitable for use with Long extension code of the code generator.
La Figura 2b es un esquema de bloques de circuito que ilustra the transitive closure of a relation r on set a whose relation matrix funcionamiento de alimentación directa del generador de códigos. Figure 2b is a circuit block scheme illustrating the direct feed operation of the generator of codes. La Figura 2c es un esquema de bloques de un generador de the transitive closure of a relation r on set a whose relation matrix ejemplar incluyendo circuitos para generar secuencias de códigos de extensión a partir de los códigos de extensión largos y de los códigos de extensión cortos.
Figure 2c is a block diagram of a exemplary code generator including circuits to generate extension code sequences from the codes of Long extension and short extension codes. La Figura 2d es una realización alternativa del circuito generador de códigos incluyendo elementos de retardo para compensar los retardos de circuito eléctrico. Figure 2d is an alternative embodiment of code generator circuit including delay the transitive closure of a relation r on set a whose relation matrix for compensate for electrical circuit delays.
Figure 3a is a graph of the points of constellation of the phase shift modulation signal Quadrature QPSK pilot extension code. Figure 3b is a graph of the points of constellation of the phase shift modulation signal Quadrature of QPSK message channel. La Figura 3c es un esquema de bloques de circuito ejemplar que lleva a cabo el método de rastrear la fase de código de what is the advantage of online marketing recibido.
Figure 3c is a circuit block scheme instance that performs the method of tracking the code phase of extension received. Figure 4 is a circuit block scheme tracking that tracks the median of the signal components received from multiple the transitive closure of a relation r on set a whose relation matrix. Figure 5a is a block diagram of the tracking circuit that tracks the centroid of the components of Signal received from multiple paths.
La Figura 5b es un esquema de bloques del correlacionador vectorial adaptable.
la respuesta Competente
Esto no me gusta.
Esto no me conviene.
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