Software-defined radio (SDR) is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which used to be only theoretically possible.
A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used.
Software radios have significant utility for the military and cell phone services, both of which must serve a wide variety of changing radio protocols in real time.
In the long term, software-defined radios are expected by proponents like the SDRForum (now The Wireless Innovation Forum) to become the dominant technology in radio communications. SDRs, along with software defined antennas are the enablers of the cognitive radio.
A software-defined radio can be flexible enough to avoid the "limited spectrum" assumptions of designers of previous kinds of radios, in one or more ways including:
- Spread spectrum and ultrawideband techniques allow several transmitters to transmit in the same place on the same frequency with very little interference, typically combined with one or more error detection and correction techniques to fix all the errors caused by that interference.
- Software defined antennas adaptively "lock onto" a directional signal, so that receivers can better reject interference from other directions, allowing it to detect fainter transmissions.
- Cognitive radio techniques: each radio measures the spectrum in use and communicates that information to other cooperating radios, so that transmitters can avoid mutual interference by selecting unused frequencies.
- Dynamic transmitter power adjustment, based on information communicated from the receivers, lowering transmit power to the minimum necessary, reducing the near-far problem and reducing interference to others, and extending battery life in portable equipment.
- Wireless mesh network where every added radio increases total capacity and reduces the power required at any one node. Each node only transmits loudly enough for the message to hop to the nearest node in that direction, reducing near-far problem and reducing interference to others.
Tawaran Khas untuk lepasan SPM/STPM/STAM/Diploma/Matrikulasi/Asasi Sempena Ulang Tahun ke 20 ICYM
- Biasiswa Penginapan dan Pengangkutan bagi Program Diploma dan Ijazah
- Pembiayaan/Penajaan Penuh daripada PTPK bagi Program Sijil
Foundation / Diploma Foundation In Information Technology Foundation In Management Diploma In Entrepreneurship Diploma In Marketing Diploma In Accountancy Diploma In Islamic Financial Planning Diploma In Culinary Arts Diploma In Hotel Management Diploma In Tourism Management Diploma In Animation Technology Diploma In Media Technology Diploma In Theatrical Arts And Technology Diploma In Multimedia Technology Diploma In Information Technology Diploma In Computer Networking Diploma In Cyber Security Diploma In Electrical Technology Diploma In Industrial Electronic Technology Diploma In Early Childhood Education Diploma In Guidance & Counseling Diploma In Aircraft Maintenance Technology Kerjasama Universiti Teknologi Malaysia Diploma In Technology Management (UTM) Diploma In Technology Management (Accounting) (UTM) Diploma In Computer Science (Information Technology) (UTM) Sarjana Muda Sains (Pembangunan Sumber Manusia) (UTM) Sarjana Muda Pengurusan (Pemasaran) (UTM) Sarjana Muda Sains Komputer (Perisian Grafik & Multimedia) (UTM) Sarjana Muda Sains Komputer (Rangkaian & Keselamatan) (UTM) Professional License Aircraft Maintenance License Technician (AML-T) DCAM-PT-66 CAT A1 Aircraft Maintenance License Engineer (AML-E) DCAM-PT-66 CAT B1-1 Sijil Kemahiran Malaysia (SKM) / Short Course Lukisan Pelan Senibina / Juruteknik Elektrik / Teknologi Automotif / Pembuatan Pastri Program Tajaan Ground Handling Management (GHM) PTPTN Bahagian Pengurusan Kemasukan Pelajar UPU KWSP YAYASAN PENERAJU UPEN PTPK TAPEM YAYASAN NEGERI ZAKAT MARA UNIVERSITI ISLAM ANTARABANGSA MALAYSIA (IIUM) UNIVERSITI KEBANGSAAN MALAYSIA (UKM) UNIVERSITI KEBANGSAAN MALAYSIA (UKM) UNIVERSITI MALAYA UNIVERSITI MALAYSIA KELANTAN (UMK) UNIVERSITI MALAYSIA PAHANG (UMP) UNIVERSITI MALAYSIA PERLIS (UNIMAP) UNIVERSITI MALAYSIA SABAH (UMS) UNIVERSITI MALAYSIA SARAWAK (UNIMAS) (KOTA SAMARAHAN) UNIVERSITI MALAYSIA TERENGGANU (UMT) UNIVERSITI PENDIDIKAN SULTAN IDRIS (UPSI) UNIVERSITI PERTAHANAN NASIONAL MALAYSIA UNIVERSITI PUTRA MALAYSIA (UPM) UNIVERSITI SAINS ISLAM MALAYSIA (USIM) UNIVERSITI SAINS MALAYSIA (USM) UNIVERSITI SULTAN ZAINAL ABIDIN (UNISZA) UNIVERSITI TEKNIKAL MALAYSIA MELAKA (UTEM) UNIVERSITI TEKNOLOGI MALAYSIA (UTM) UNIVERSITI TEKNOLOGI MARA UNIVERSITI TUN HUSSEIN ONN MALAYSIA (UTHM) UNIVERSITI UTARA MALAYSIA (UUM)