Confronta i metodi
Esamina i metodi selezionati fianco a fianco; le righe che differiscono sono evidenziate.
| Codice spazio-temporale a blocchi di Alamouti× | Orthogonal Frequency Division Multiplexing (OFDM)× | Teorema della Capacità di Canale di Shannon× | Codifica Turbo con Decodifica Iterativa× | |
|---|---|---|---|---|
| Campo | Telecomunicazioni | Telecomunicazioni | Telecomunicazioni | Telecomunicazioni |
| Famiglia | Process / pipeline | Process / pipeline | Process / pipeline | Process / pipeline |
| Anno di origine≠ | 1998 | 1971 | 1948 | 1993 |
| Ideatore≠ | Siavash Alamouti | Weinstein and Ebert | Claude Shannon | Claude Berrou, Alain Glavieux, and Punya Thitimajshima |
| Tipo≠ | space-time coding scheme | multicarrier modulation scheme | fundamental theoretical bound | iterative error-correcting code |
| Fonte seminale≠ | Alamouti, S. M. (1998). A simple transmit diversity technique for wireless communications. IEEE Journal on Selected Areas in Communications, 16(8), 1451-1458. DOI ↗ | Weinstein, S. B., & Ebert, P. M. (1971). Data transmission by frequency-division multiplexing using the discrete Fourier transform. IEEE Transactions on Communication Technology, 19(5), 628-634. DOI ↗ | Shannon, C. E. (1948). A mathematical theory of communication. Bell System Technical Journal, 27(3), 379-423. DOI ↗ | Berrou, C., Glavieux, A., & Thitimajshima, P. (1993). Near Shannon limit error-correcting coding and decoding: Turbo-codes. In Proceedings of the IEEE International Conference on Communications (ICC), 1064-1070. DOI ↗ |
| Alias≠ | space-time coding, transmit diversity | multicarrier modulation | channel capacity, information theory bound | iterative decoding, concatenated codes |
| Correlati | 5 | 5 | 5 | 5 |
| Sintesi≠ | The Alamouti code is an elegant space-time coding scheme that provides full transmit diversity using two antennas and a simple linear receiver. Introduced by Siavash Alamouti in 1998, it requires no channel state information at the transmitter, achieves the same bit-error rate as a single-antenna system with receiver diversity, and uses linear processing for decoding. The Alamouti code has become the de facto standard for transmit diversity in cellular systems and is adopted in LTE, WiFi, and many 5G protocols. | OFDM is a multicarrier modulation technique that divides a wideband channel into many narrowband orthogonal subcarriers. Introduced by Weinstein and Ebert in 1971, it exploits the duality between time and frequency domains to efficiently use spectrum while mitigating intersymbol interference in frequency-selective channels. OFDM is now the standard for high-speed wireless systems including WiFi, cellular LTE, and digital broadcasting. | Shannon's channel capacity theorem, published in 1948, establishes the maximum rate at which information can be reliably transmitted over a noisy channel. Expressed as C = B log2(1 + S/N) for additive white Gaussian noise (AWGN), it is a fundamental bound in information theory and communications engineering. Shannon proved that reliable communication is possible at any rate below capacity, and impossible above it. This theorem underpins the design of all modern communication systems and motivates coding theory, modulation, and signal processing techniques. | Turbo codes, introduced by Berrou, Glavieux, and Thitimajshima in 1993, are a landmark in channel coding history. They achieve performance within 0.5 dB of the Shannon limit—the theoretical boundary for reliable communication—a feat previously thought impossible with practical complexity. Turbo codes use concatenated convolutional codes with an interleaver and iterative decoding via belief propagation. They were adopted in 3G (UMTS) and remain important in 4G/5G systems alongside LDPC codes. |
| ScholarGateInsieme di dati ↗ |
|
|
|
|