Abstract:
단말기 및 기지국, 그리고, 그들의 주파수 센싱 방법이 개시될 수 있다. 단말기 또는 기지국은 입력신호를 수신할 수 있는 전체 주파수 대역 중 주파수 센싱이 필요한 대역을 필터링할 수 있다. 또한, 필터링된 대역에 대해 주파수 센싱을 적용함으로써, 신호의 검출 능력과 속도를 향상시킬 수 있다. 가변대역통과필터, 다운 샘플링, 주파수 센싱
Abstract:
PURPOSE: An emergency network device and a data communications method are provided to process the communications of the terminal using a pilot channel, in case the communications of the terminal is impossible by using the RAT(Radio Access Technology). CONSTITUTION: A determining unit(510) monitors whether RAT of a wireless network normally operates or not. A time slot assignment circuit(520) assigns a cognitive pilot channel to the terminal according to the control function of the determining unit. A data communications part(530) processes the data communications through the cognitive pilot channel with the terminal. The data communications part transmits or receives the voice and the image through the terminal.
Abstract:
PURPOSE: An apparatus and method for complex constant multiplier and FFT processor are provided to reduce size, complexity, and power consumption of a complex constant multiplier and an FFT processor by configuring the complex constant multiplier with 5 real number multipliers. CONSTITUTION: A first and a second multiplier select and output an imaginary part or real part of complex input value as a first and a second input value respectively based on a rotation factor table. A first real number multiplier(310) multiplies the sum of the first and the second triangular function value by the first input value. A second real number multiplier(320) multiplies the subtraction of the first and the second triangular function value by the second input value. A two's compliment arithmetic unit(330) calculates two's compliment of the first input. An adder adds the output value of the two's compliment arithmetic unit and the second input value. A third real number multiplier(350) multiplies the output value of the adder by the second triangular function value.
Abstract:
PURPOSE: A device and a method for Fourier transform are provided to reduce registers and adders for Fourier transform, thereby reducing the capacity of hardware of the Fourier transform device. CONSTITUTION: A stage part performs the first butterfly operation based on two divided sequences(S100). The second stage unit performs the second butterfly operation based on the first operation sequence(S110). The first rotation factor application unit applies the first rotary factor to the second operation sequence(S120). The third stage unit performs the third butterfly operation based on the first rotary factor applied sequence(S130). The fourth stage unit performs the fourth butterfly operation based on the third operation sequence(S140).
Abstract:
An apparatus and a method for viterbi decoding are provided to increase an operation speed by using a block processing decoding method. A viterbi decoder includes a distributor(281), a plurality of memory banks(283a-283h), a plurality of switches(285a-285h) and a plurality of decoding units(287a,287b). The distributor distributes the plurality of bits inputted from the de-puncturer in a block data unit. The plurality of memory banks store the block data inputted from the distributor. The plurality of switches are connected to the plurality of memory banks respectively. Each switch outputs block data stored in one memory bank. Each decoding unit is connected to a part of switches. Each decoding unit performs the viterbi decoding algorithm about block data and outputs a part of block data.
Abstract:
A method and an apparatus for detecting a time-frequency code in a multiband OFDM UWB(Ultra-Wide Band) system are provided to detect the time-frequency code quickly by decreasing the number of detecting steps between a PHY(PHYsical) layer and an upper layer. An apparatus for detecting a time-frequency code in a multiband OFDM(Orthogonal Frequency Division Multiplexing) UWB system includes a controller(305) and a correlator(303). When a time-frequency code search start signal is received from a MAC(Media Access Control) receiver, the controller outputs a band select signal to an RF receiver to calculate a correlation value, and outputs a preamble select signal for every symbol period. The correlator stores information on a preamble pattern, selects the stored preamble according to the preamble select signal from the controller, and calculates a correlation value for a digital signal from the RF(Radio Frequency) receiver. When a peak signal is inputted according to the correlation value, the controller determines the time-frequency code as a current time-frequency code, and delivers the determined time-frequency code to the MAC receiver.
Abstract:
An apparatus and a method for detecting a preamble packet in an OFDM(Orthogonal Frequency-Division Multiplexing) system are provided to improve the accuracy of detecting the preamble packet even in case that an interference signal exists or received signal power is small. An apparatus for detecting a preamble packet in an OFDM system includes a cross-correlation calculating unit(21), a delay unit(22), a power measuring unit(23), and a dividing unit(24). The cross-correlation calculating unit calculates the cross-correlation value with the stored preamble pattern value for an OFDM symbol(N-point) period according to the reception of a signal. The delay unit delays the cross-correlation value calculated in the cross-correlation calculating unit as much as a protection(M-point) period. The power measuring unit measures the received power for the protection period. The dividing unit divides the cross-correlation value delayed in the delay unit by the power value measured in the power measuring unit to calculate the final cross-correlation value.
Abstract:
1. 청구범위에 기재된 발명이 속한 기술분야 본 발명은 DS-CDMA UWB 시스템을 위한 병렬처리구조의 등화기 및 그 방법에 관한 것임. 2. 발명이 해결하려고 하는 기술적 과제 본 발명은 병렬처리 구조의 등화기에서 복수( L 개)의 필터탭계수 갱신부(WUB)마다 개별적으로 필터탭계수를 갱신하는 기존 방식과 달리, 하나의 필터탭계수 갱신부(WUB)만을 사용하여 필터탭 계수를 갱신하고 그 갱신된 값을 L 개의 필터부(FB)에 전달하여 송신 심볼을 추정하게 함으로써, DS-CDMA UWB 모뎀 수신부에 사용되는 등화기의 복잡도 및 전력 소모를 현저히 감소시킬 수 있는, DS-CDMA UWB 시스템을 위한 병렬처리구조의 등화기 및 그 방법을 제공하는데 그 목적이 있음. 3. 발명의 해결방법의 요지 본 발명은, DS-CDMA UWB 시스템을 위한 병렬처리구조의 등화기에 있어서, 상기 등화기가 훈련모드로 동작하면 다수의 입력신호들 중에서 어느 하나의 입력신호(훈련용 입력신호)에 대하여 필터링을 수행하고, 상기 등화기가 심볼결정모드로 동작하면 입력신호 모두에 대하여 병렬적으로 필터링을 수행하기 위한 필터 수단; 상기 훈련모드의 경우에는 상기 필터 수단의 출력값과 훈련심볼로부터 심볼오류값을 구하고, 상기 심볼결정 모드의 경우에는 각각의 입력신호에 대한 상기 필터 수단의 출력값으로부터 해당 송신심볼값을 추정하고 송신심볼값이 추정된 입력신호 들 중에서 어느 하나의 입력신호(심볼오류 산출용 입력신호)에 대해서는 해당 추정 송신심볼값의 오차(심볼오류값)를 구하기 위한 심볼 결정 수단; 및 상기 훈련용 입력신호 또는 상기 심볼오류 산출용 입력신호와 상기 심볼 결정 수단에서 구한 심볼오류값을 이용해서 상기 필터 수단의 필터탭 계수를 갱신하여 상기 필터수단으로 전달하기 위한 필터탭계수 갱신 수단을 포함함. 4. 발명의 중요한 용도 본 발명은 DS-CDMA UWB 시스템에서의 등화기 등에 이용됨. DS-CDMA, UWB, 병렬처리구조, 등화기, 필터탭계수 갱신부, WUB(Weight Update Blcok), 필터부, FB(Filter Block)