Conventional beamforming can beseen as a sort of 2D cell-specific beamforming. The UE data to be transmittedis processed in accordance with the channel information only in the horizontal dimension.
Once several UEs are close to each otherandlocated inthe cell edge area, they own the same power ofdesired signalbut will sufferserious intercell interference.
intercell interferencedecreases the performance of cell edge UE dramatically
3D MIMO can be seen as a dynamicinterference cancellation method, which aimsto eliminate intercell interference coming from neighbor cells andimprove the throughput of cell edge UE through 3D dynamic beamforming. For eachUE, since the introduction of vertical dimension, difference in height betweenBS and UE has been taken into account, and UE’s position should be consideredin three-dimension. According to both horizontal and vertical directions of thespecific UE, transmitting beam generated by 3D antennas can be divided intoboth horizontal and vertical dimensions, which means it has much less influenceon other UEs.
Conventional 2D MIMO beamforming.
3D dynamic beamforming in horizontal sight.
3D dynamic beamforming in vertical sight.
그 사람은 프로그래머가 아니기 때문이다. 그는 좀비다. 언제 그대를 물어뜯을지 모르는 영혼 없는 존재다.
Baseband is type of transmission that is using current to send signal over the wire as digital wave. It can transmit only one signal at a time, due to requirement of the exclusive use of the wire. This type of transmission is allowing only on device to transmit in the network at one time, while other devices need to wait for the end of transmission.
While in some cases baseband supports full-duplexing, in most cases the half-duplexing is used for sending signals upstream and downstream.
You can read more about Full and Falf Duplex comparison here.
Ethernet is using baseband for LANs. If the data is needed to be send to a server, network interface card is making request to use the wire. While the wire is busy, NIC retries its request. When the wire is available, the data is being sent. The process takes milliseconds and is not noticeable by user.
Broadband is using analog signal that is modulated. It is used to transmit cable TV to premises. Broadband is using different frequencies which increases amount of data it can carry at one time. The amount of data is higher 25 times compared to the baseband. Usually broadband is transmitting data in one direction, towards user. If user needs to send data, an individual channel is used for data and special amplifiers are used for data separation. While broadband signal can travel longer distances it is having additional expenses due to the use of extra equipment.
In Baseband, data is sent as digital signals through the media as a single channel that uses the entire bandwidth of the media. Baseband communication is bi-directional, which means that the same channel can be used to send and receive signals. In Baseband, frequency-division multiplexing is not possible. (Multiplexing (short muxing) is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium.)
Broadband sends information in the form of an analog signal. Each transmission is assigned to a portion of the bandwidth, hence multiple transmissions are possible at the same time. Broadband communication is unidirectional, so in order to send and receive, two pathways are needed. This can be accomplished either by assigning a frequency for sending and assigning a frequency for receiving along the same cable or by using two cables, one for sending and one for receiving. In broadband frequency-division multiplexing is possible.
의 계수를 계산하는 가장 간단한 방법은 가우스 소거법을 이용하는 것이다. 가우스 소거법을 행하여 행렬을 행 사다리꼴 형태로 만들어도 계수는 보존된다. 이때 0이 아닌 행의 숫자가 곧 행렬의 계수가 된다.
예를 들어 다음과 같은 4×4 행렬에서
첫 번째 열과 세 번째 열은 선형독립이지만, 두 번째 열은 첫 번째 열의 두배와 같고 네 번째 열은 첫 번째 열과 세 번째 열의 합과 같으므로 의 계수는 2이다. 가우스 소거법을 통해 다음과 같이 나타낼 수 있다.
이때 0이 아닌 행이 두개임을 확인할 수 있다.