Mehrträgeransätze

Mehrträgeransätze, also known as multi-carrier approaches, are a class of communication techniques that divide a single data stream into multiple sub-streams, each transmitted over a different carrier frequency. This contrasts with single-carrier systems that transmit all data over one frequency.

The most prominent example of a Mehrträgeransatz is Orthogonal Frequency Division Multiplexing (OFDM). OFDM divides the available bandwidth into a large number of closely spaced orthogonal sub-carriers. This orthogonality ensures that the sub-carriers do not interfere with each other, even though they may overlap in frequency. Each sub-carrier is modulated with a portion of the original data stream, typically using a form of Phase Shift Keying (PSK) or Quadrature Amplitude Modulation (QAM).

The primary advantage of Mehrträgeransätze is their robustness against frequency-selective fading, a common problem in wireless communication where different frequencies are attenuated by different amounts. By distributing data across many sub-carriers, the impact of fading on any single sub-carrier is reduced, leading to a more reliable transmission. They also offer a simpler implementation for equalization compared to single-carrier systems in the presence of multipath propagation.

Mehrträgeransätze have found widespread application in modern communication standards, including Wi-Fi (IEEE 802.11a/g/n/ac/ax), 4G LTE, 5G NR, and digital broadcasting systems like DAB and DVB-T. The flexibility and efficiency of these techniques have made them a cornerstone of high-speed wireless and wired data transmission.