transmit vector) with the eigenvector(s) of the channel.
To prevent a potential misunderstanding here, precoding does not cancel out the impact of the channel, but it aligns the vector containing the transmit symbols (i.e. This technique will reduce the corrupted effect of the communication channel.įor example you are sending the information s and it turns out to be the detection problem in Gaussian channels which is simple. The receiver is a simple detector, such as a matched filter, and does not have to know the channel state information. the transmitter sends the coded information to the receiver to achieve pre-knowledge of the channel. Precoding is a technique that exploits transmit diversity by weighting the information stream, i.e.
DOWNLINK LOGIN FULL
3.1 Linear precoding with full channel state information.
3 Precoding for Multi-user MIMO Systems.2.1 Statistical channel state information.2 Precoding for Point-to-Point MIMO Systems.Precoding in the downlink of cellular networks, known as network MIMO or coordinated multipoint (CoMP), is a generalized form of multi-user MIMO that can be analyzed by the same mathematical techniques. In point-to-point systems, some of the benefits of precoding can be realized without requiring channel state information at the transmitter, while such information is essential to handle the inter-user interference in multi-user systems. In multi-user MIMO, the data streams are intended for different users (known as SDMA) and some measure of the total throughput (e.g., the sum performance or max-min fairness) is maximized. In point-to-point systems, precoding means that multiple data streams are emitted from the transmit antennas with independent and appropriate weightings such that the link throughput is maximized at the receiver output. In order to maximize the throughput in multiple receive antenna systems, multi-stream transmission is generally required. When the receiver has multiple antennas, single-stream beamforming cannot simultaneously maximize the signal level at all of the receive antennas. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas with appropriate weighting (phase and gain) such that the signal power is maximized at the receiver output. Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. A licensed downlink station is required to meet strict technical standards with respect to site location, elevation angle, and antenna directivity.For other uses, see Pre-code (disambiguation).
There are four rules that address the interference problem: site requirements, power limits, minimum elevation angle and antenna directivity. The principal technical rules governing the operation of uplink earth stations have the purpose of minimizing interference to microwave receiving stations operating in the C band, 5925 to 6425 MHz. The chapter focuses on FCC Rules and procedures governing the installation and technical operation of uplink and downlink earth stations. The International Telecommunications Union governs radio services on an international level. The regulation of satellite communications also requires international agreement. Abstract: The Federal Communications Commission (FCC) was established by the Communications Act of 1934, which gave it very broad authority to regulate interstate wired and wireless communications within the United States.
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