ABSTRAKSI: Sekarang ini keamanan dan kerahasiaan telah menjadi suatu hal yang penting dalam teknologi informasi. kebutuhan akan sistem komunikasi yang kebal terhadap masalah interferensi dan penyadapan mengakibatkan munculnya sistem komunikasi spread spectrum pada pertengahan tahun 1950. Spread spectrum dapat diartikan sebagai teknik pengiriman sinyal informasi yang menggunakan suatu kode untuk menebarkan energi sinyal informasi dalam bandwidth yang jauh lebih lebar dibanding bandwidth sinyal informasi. Dalam spread spectrum ada beberapa macam cara yang digunakan, yaitu : Direct Sequence Spread Spectrum (DSSS), Frequency Hopping Spread Spectrum (FHSS), Time Hopping Spread Spectrum (THSS).
Pada penelitian Tugas Akhir ini dilakukan perancangan dan realisasi penerima suara spread spectrum menggunakan demodulasi FSK. Perangkat utama pada sistem penerima terdiri dari demodulator FSK frequency hopping yang direalisasikan dengan sistem VCO pada frekuensi 159 MHz.
Dengan menggunakan Teknik Frequency Hopping Spread Spectrum perancangan tugas akhir ini sistem penerima belum dapat terealisasikan dengan sempurna penyebabnya terdapat blok filter yang belum bekerja secara sempurna dikarenakan pendekatan nilai komponen yang jauh dari perancangan awal. Tetapi beberapa blok penerima sudah berhasil direalisasikan diantaranya ialah blok Pre Amplifier, Mixer I, Mixer II, demodulator FSK, Osilator, sistem minimum mikrontroler, resistor ladder dan LPF Aktif 4 KHz itu disebabkan karena dalam perancangan blok tersebut menggunakan IC sehingga sistem pada blok tersebut stabil dan berjalan sesuai dengan yang diinginkan.Kata Kunci : Frequency Hopping Spread Spectrum, demodulasi, Tahan jamming.ABSTRACT: Now is the security and confidentiality has become an essential in information technology. the need for communications systems that are immune to interference issues and intercepts resulted in the emergence of spread spectrum communication system in mid-1950. Spread spectrum can be interpreted as an information signal transmission technique that uses a code to spread the information signal energy in a much wider bandwidth than the information signal bandwidth. In spread spectrum there are several kinds of ways in which, such as : Direct Sequence Spread Spectrum ( DSSS), Frequency Hopping Spread Spectrum ( FHSS), Time Hopping Spread Spectrum ( THSS).
In the present study was conducted Final design and realization of sound spread spectrum receiver using FSK demodulation. The main device on the receiving system consists of frequency hopping FSK demodulator is realized with the system at a frequency of 159 MHz VCO.
Using Frequency Hopping Spread Spectrum Technique drafting this final recipient system can not be realized with a perfect cause there are filters that block has not worked perfectly because the value of the component approach that is far from the initial design. But a few blocks of which the recipient has successfully realized the block is Pre Amplifier, Mixer I, II Mixer, FSK demodulator, oscillator, the minimum system controller, the resistor ladder and LPF Active 4 KHz was caused because in the design of the block using the IC so that the system is stable on the block and run in accordance with the desiredKeyword: Frequency Hopping Spread Spectrum, Demodulasi, Tahan jamming.