摘要:
The present invention has an object to provide a filter circuit for communication generative an effective digital output as well as an analog output in a filter circuit of low electric power consumption. The function speed of an A/D converting circuit is minimized by intermittently holding an analog output signal according to an experience that peak detection can be performed by partially sampling the signal after the acquisition.
摘要:
The present invention has an object to provide a filter circuit for communication generative an effective digital output as well as an analog output in a filter circuit of low electric power consumption. The function speed of an A/D converting circuit is minimized by intermittently holding an analog output signal according to an experience that peak detection can be performed by partially sampling the signal after the acquisition.
摘要:
The present invention provides a system for soft handoff, which processes in high speed. A system according to the present invention substantially realizes a multiplication by a circuit for classifying received signals from a plurality of cell site stations once held in an analog sampling and holding circuit into two groups, multiplication and accumulation, by a small circuit of low electric power consumption.
摘要:
A communication method and system which can enlarge the communication capacity using a rather simple system. The communication method and system provides different spreading codes to two signal systems at a receiving station.
摘要:
The present invention provides a matched filter circuit available for processing long P/N codes in a small size circuit. A matched filter circuit according to the present invention performs the following processes in the proposed invention: i) sampling and holding circuits multiply part of the number of a long code; ii) multipliers are input in parallel to the sampling and holding circuit from the first multiplier register which can hold as many PN codes as the number of the sampling and holding circuits in i); iii) the PN codes are stored in the second multiplier register of the same capacity of the first multiplier resister when there is a PN code to be used sequentially to be PN codes; and iv) the PN codes in the second multiplier register are transmitted in parallel to the first multiplier register. The PN code is input to the second multiplier register in serial.
摘要:
A matched filter circuit for mobile communications is disclosed. The circuit may be fabricated in a small size using large-scale integration and can perform high-speed processing and double sampling at a reduced rate of power consumption. In one embodiment, a plurality of sampling and holding circuits each including a switch are divided into two groups. A control circuit successively closes one of the switches in the first group every chip time, while successively closing one of the switches in the second group at a timing shifted by one-half chip time from that of the first group, thereby enabling a double-sampling operation. Outputs of the sampling and holding circuits in each group are summed by an analog circuit with a high degree of linearity, resulting in a high processing speed combined with a reduced circuit size and power consumption.
摘要:
The present invention realizes a rapid and efficient cell search and small-size instrument for an asynchronous DS-CDMA cellular system. This cell search detects the correlation between the received signal and the short code of the control channel, and matched filter 22 detects the maximum electric power correlation peak location. Next, using correlators 28-1 to 28-n which are parallelly set in a plurality for RAKE processing with plurality, identifies the long code that is set in the system with the detected long code timing. After the long code is synchronized, a multipath signal is received using 28-1 to 28-n, and the data is judged by RAKE processing. When peripheral cell search is executed, after long code timing is detected by using matched filter 22, the long code of the candidate peripheral cell is designated using the same matched filter. Handover is safely realized by receiving the signal from the connected base station by correlators 28-1 to 28-n, and the base station signal through handover by 22.
摘要:
The present invention has an object to provide a matched filter circuit which is possible to synchronize a spreading code with an input signal. A matched filter according to the present invention samples input signal in response to three clocks from the first to the third shifted by a half cycle of a sampling signal so as to judge whether the sampling clock is ahead or behind of the input signal according to signs of input signal sampled. One clock is selected to be the sampling clock.
摘要:
A signal reception apparatus in the spread spectrum communication system requires only a small amount of circuitry and consumes a small amount of electric power. A quadrature detector decomposes received signals into in-phase components and quadrature components, and supplies them to a complex-type matched filter. The complex-type matched filter de-spreads the in-phase components and the quadrature components and sends them to a multi-path selector. The multi-path selector selects, from among the received de-spread signals, multiple paths having high levels of signal electric powers and sends the received signals of the selected paths to multiple phase correction blocks. Analog operation circuits calculate phase errors of the received signals of two successive pilot symbol blocks for each path. An analog operation circuit corrects the phases of the received signals of the information symbol block that has been received between the two successive pilot symbol blocks. A rake combiner synchronously combines the phase-corrected de-spread received signals of each path.
摘要:
The present invention provides a path-diversity system featuring a small-size phase compensating circuit. This circuit calculates a compensating coefficient according to the signals of a pilot block or a pair of pilot blocks surrounding an information block, and then compensates information signals thereafter by the calculated compensating coefficient.