摘要:
A digital RF receiver does not use a separate receiver according to a mode and a band for multi-mode reception, MIMO reception, and bandwidth extension reception, and changes only setting variables in a single receiver structure so as to implement multi-mode reception, MIMO reception, bandwidth extension reception, and/or simultaneous multi-mode operation, such that complexity of the receiver, development cost, and power consumption can be reduced.
摘要:
The present invention relates to a single frequency synthesizer based FDD transceiver. A single frequency synthesizer generates and provides a carrier frequency so that frequency up-conversion and frequency down-conversion can be performed at the time of transmission and reception. Accordingly, the area, power consumption, and design complexity of the entire system can be reduced, and the performance of the system can be improved.
摘要:
Provided are a flexible bit rate code vector generation method and a wideband vocoder employing the same. This invention implements a flexible bit rate by getting three code vectors which are composed of 24, 16, and 8 pulses, at a time in a search process, through improvement of an algebraic codebook search process in a wideband AMR-WB vocoder. The method includes the steps of: performing a preprocess, wherein the preprocess divides a sub-frame by tracks and decides a pulse position having a maximum value in each track; among a plurality of pulses to be searched, fixing a same number of pulses as the tracks to the position with the maximum value of each track sequentially, and searching optimal positions having a minimum error with a target signal by combining two pulses in two consecutive tracks for the remaining pulses; and creating a code vector with flexible bit rate.
摘要:
A hybrid trace back apparatus and a high-speed Viterbi decoding system having the same are disclosed. The hybrid trace back apparatus includes: a register exchanging unit for receiving survivor values of each states from a path metric calculator, and obtaining a block survival value through a register exchange operation as much as a bit length for a block trace back operation; a first storing unit for the register exchange operation; a second storing unit for storing the block survival value obtained through the register exchange operation until the block survival value is written in a block trace back memory; and a block trace back unit for outputting decoded data by performing a block trace back operation while writing a value of the second storing unit.
摘要:
Provided are a flexible bit rate code vector generation method and a wideband vocoder employing the same. This invention implements a flexible bit rate by getting three code vectors which are composed of 24, 16, and 8 pulses, at a time in a search process, through improvement of an algebraic codebook search process in a wideband AMR-WB vocoder. The method includes the steps of: performing a preprocess, wherein the preprocess divides a sub-frame by tracks and decides a pulse position having a maximum value in each track; among a plurality of pulses to be searched, fixing a same number of pulses as the tracks to the position with the maximum value of each track sequentially, and searching optimal positions having a minimum error with a target signal by combining two pulses in two consecutive tracks for the remaining pulses; and creating a code vector with flexible bit rate.
摘要:
In case microcontroller and digital signal processing blocks are used together in one chip, there has been a problem in which the synchronization of the clocks are not consistent with each other when sending a signal from one block to another. In addition, when a reference clock is activated during a change of input signal, an incomplete interval has occurred. Accordingly, in order to solve the above mentioned problem, the present invention discloses a synchronizing circuit which uses a latch circuit("RS") consisted of NAND gates to synchronize an asynchronous input data and a reference clock, thereby solving the problem in which an incomplete interval occurs.
摘要:
A method for stable channel estimation to increase frequency band efficiency that is lost by using a pilot, and to reduce the complexity and the sensitivity to channel zero. The method includes generating an i-th symbol block Si including N carriers, performing an inverse fast Fourier transform (IFFT) operation on the i-th symbol block, and forming an orthogonal frequency division multiplexing (OFDM) symbol block. The method also includes attaching a guard interval sample in front of the i-th OFDM symbol block Ui and forming at least one OFDM symbol block Ui,cp. The method further includes modeling the formed OFDM symbol block Ui,cp with a channel finite impulse response (FIR) filter and estimating channel impulse response using signals yi received through a channel.
摘要:
Provided is a receiver of a multi-input multi-output system using multiple antennas, the receiver including: a first multiplying unit for multiplying a vector r received via the antenna by a Hermitian matrix Q; a candidate transmitting vector generating unit for detecting a signal on a lowest modulation order transmitting antenna from the received vector y output from the first multiplying unit, creating as many symbol candidates as the modulation order of the detected signal, and generating a candidate transmitting vector using each symbol candidate; a transmitting vector determining unit for obtaining a distance between each candidate transmitting vector generated by the candidate transmitting vector generating unit and the received vector y to determine a final transmitting vector; and a demodulating unit for demodulating the final transmitting vector determined by the transmitting vector determining unit. Since the receiver detects a transmitting vector with reference to a signal on a lowest modulation order transmitting antenna, the receiver can have a simpler structure.
摘要:
A multipath searching device includes a radio front-end for converting a received radio signal into a baseband signal and for outputting the baseband signal. A profile calculating unit is included for calculating and outputting the multipath profile of the baseband signal. A first detector determines whether or not the radio signal traveled along a multipath is having a short-delay path by comparing the peak value of the multipath profile with a profile value of a predetermined position time interval before or after the peak of the multipath profile. A path selector receives the multipath profile and the detection result of the first detector, generates time delay information for each path, and separates many paths along which the radio signal traveled. A receiving unit receives the time delay information of the paths, despreads the baseband signal, and combines despread signals.
摘要:
In the apparatus and method for separating carrier of multicarrier wireless communication receiver system, each carrier separation is performed after a quantization in a wireless communication receiver system such as a received multicarrier CDMA (Code Division Multiple Access) etc., to thereby reduce the whole number of quantizers and separate multicarrier from a received signal. For that, the apparatus for separating the carrier of the multicarrier wireless communication receiver system includes an internal oscillating unit for generating internal multicarrier; a plurality of frequency transition units for respectively down-converting the multicarrier generated by the internal oscillating unit and moving it to frequency of “0” as a frequency center; and a plurality of filtering units for individually filtering the respective carrier moved by the plurality of frequency transition units to the frequency center as the frequency of “0”, through a low frequency pass band and for providing it as an input of a rake receiver.