Abstract:
Se expone un sistema para realizar una operacion mariposa de agregar-comparar- seleccionar (ACS) en una implementacion del algoritmo Viterbi. El sistema incluye un primer elemento de memoria (145) para almacenar una pluralidad de metricas del estado fuente; un multiplexor (670) que es capaz de seleccionar entre una primera y segunda trayectorias de operacion con base en ritmos pares e impares, un mecanismo ACS (600), que calcula las metricas del estado blanco para cada una de las metricas del estado fuente. Se utiliza una segunda memoria acoplada al mecanismo ACS y el multiplexor, para almacenar temporalmente las metricas blanco. Por lo tanto, el multiplexor selecciona la primera trayectoria de operacion durante los ritmos pares y suministra las metricas del estado fuente desde la primera memoria hacia el mecanismo ACS para generar las metricas del estado blanco. Durante los ritmos impares, el multiplexor selecciona la segunda trayectoria de operacion para tener acceso a la segunda memoria y utilizar las metricas del estado blanco calculadas anteriormente, como las metricas del estado fuente intermedio.
Abstract:
A voice and data communication system and method for receiving symbols for a plurality of channels into chunks included within buffers, each chunk holding symbols for only a corresponding one of the plurality of channels. As complete frames are received and decoded, the chunks holding the symbols, that are decoded, are freed up to be used for reception of newly arriving symbols included in newly arriving frames.
Abstract:
A serial Viterbi decoder having a chainback cache is provided for use in a mobile telephone. In one embodiment described herein, the decoder includes a branch error metric block, an add-compare-select unit, and a chainback block including a chainback RAM, a full chainback cache and chainback controller circuitry. The chainback cache caches decision bits from previous process cycles such that full chainback operations need not always be performed. The chainback cache is configured to cache on all reads. With the chainback cache, significant savings in power consumption and processing time may be achieved with only a relatively modest increase in the amount of circuitry required. In another embodiment, a full chainback cache is not provided. Rather, the chainback block instead includes an L+1 bit RAM, an updown counter and a shift register configured to emulate a chainback cache. In still another embodiment, an L bit shift register is employed instead of the combination of the L+1 bit RAM and updown counter. In the various embodiments, the chainback block may be configured to perform only one chainback read in each process cycle or may be configured to perform m chainback reads in each process cycle. In still other embodiments, the chainback block is configured to perform chainback operations based on a through b reads where the cache is accessed for each read after a reads have been done until b reads have been performed or a match is obtained. In still further embodiments, the chainback block is configured to perform chainback operations over multiple process cycles rather than only a single process cycle.
Abstract:
A voice and data communication system and method for receiving symbols for a plurality of channels into chunks included within buffers, each chunk holdin g symbols for only a corresponding one of the plurality of channels. As comple te frames are received and decoded, the chunks holding the symbols, that are decoded, are freed up to be used for reception of newly arriving symbols included in newly arriving frames.
Abstract:
A resource allocator for allocating at least two different types of hardware resources for users within a communication system, wherein the system supports up to a first predetermined number of users of one particular type and a second predetermined number of users of a second particular type. The resource allocator provides a mapping of resources, either from fixed resources to shared resources or from shared resources to fixed resources, which is both cost effective and transparent to software.
Abstract:
A voice and data communication system and method for receiving symbols for a plurality of channels into chunks included within buffers, each chunk holding symbols for only a corresponding one of the plurality of channels. As complete frames are received and decoded, the chunks holding the symbols, that are decoded, are freed up to be used for reception of newly arriving symbols included in newly arriving frames.
Abstract:
A voice and data communication system and method for receiving symbols for a plurality of channels into chunks included within buffers, each chunk holding symbols for only a corresponding one of the plurality of channels. As complete frames are received and decoded, the chunks holding the symbols, that are decoded, are freed up to be used for reception of newly arriving symbols included in newly arriving frames.