ANALISIS KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ DAN ¾ MENGGUNAKAN 4 DAN 3 ANTENA MODULASI M-PSK BERBASIS PERANGKAT LUNAK

In wireless communications has one characteristic that is the phenomenon of multipath fading, it takes a technology that could make the reflection signal does not eliminate the primary signal. The use of multiple antennas at the transmitter and the receiver is expected to result in improved quality of the wireless communication service. This technique is known as MIMO (Multiple Input Multiple Output). One scheme is MIMO STBC (Space Time Block Code), which has a subclass of OSTBC (Orthogonal Space Time Block Code). The principle OSTBC is sending some signal replicas information on the independent channel fading in orthogonal signal format, so that at least one signal receiver who did not experience the worst fading. So with the process of sending data faster and more reliable and mark with BER (Bit Error Rate) is low. The test results obtained on average use of the antenna, the more the better values obtained difference SNR BER 10-3 ± 2 to ± 5dB of each receiving antenna. Keywords : Multipath fading, OSTBC (Orthogonal Space Time Block Code), rat

Analisa Performansi Low Density Parity Check Code Pada Sistem CDMA

The purpose of this final project is to analyze the performance of Low Density Parity Check Code for CDMA system. The analyze is to compare the simulation program of LDPC-CDMA with different parity check matrix LDPC and different amount of active user. The comparison for the system is compare based on Bit Error Ratio for the systems. So it could be declare with using what decoding method it can perform better. For the result of Bit Error Rate, the system LDPC for CDMA with different matrix has different value too. For the small matrix of LDPC has value of BER smaller than bigger matrix of LDPC. Then, for amount of many active user that has BER many too with equal little of active user. Key Words : LDPC, CDMA, BER, Bit Flip, Sum Product

PERBANDINGAN KINERJA LDPC PADA KANAL AWGN DENGAN MODULASI QPSK DAN BPSK

Low Density Parity Check (LDPC) codes are one class of linear block coding techniques. The name comes from the characteristics of the LDPC parity check matrix was that only contain a little bit of '1 'if compared with the number of bits of '0'. The main advantage of this is the LDPC coding techniques can yield performance very close to the value of various kinds of channel capacity (Shannon's Limit), and has a linear decoding process. LDPC was first introduced by Gallager in his PHD thesis on the year 1960. Channel coding (channel coding) on a digital system is one way to protect digital information against errors that may occur during signal transmission by way of redundancy menambahan number of digits in the number of digits of information to be transmitted. LDPC (Low Density Parity Check) code is defined as a linear block code which has a low density that can produce a low BER(bit error rate). The aim of this thesis is to compare the performance of the use of LDPC code in AWGN channel and will be applied in the QPSK and BPSK modulation. Simulation will be applied under matlab software. The parameters that will be compared is the comparison of BER.. Key word : LDPC, AWGN, QPS

Perbandingan Kinerja LDPC (Low Density Parity Check) Dengan Metode Decoding Log Domain Sum Product Pada Kanal AWGN Dan Multipath Fading

As an effect of the globalization era, telecomunication technology, especially in wireless comunication system is forced to prepare high data rate with reliable Quality of Services (QOS) with Low Bit Error Rate (BER) and very small power. The problem in mobile comunication is AWGN and multipath fading, which affected the rising of error data receive on receiver side. This final project simulates the coding tehnique�s Low Density Parity Check Code (LDPC) on AWGN and multipath fading. Encoding on transmitter with sparse matrx method based on Approximation Lower Triangular in rate ½.While decoding apply with decoding sum product log domain. The simulation result is analyzed With a different matrix size, the result of LDPC isn�t to variably in LDPC performance. At different iteration, more iteration influence LDPC with the result that good. BER acquired 10-3 in AWGN channel acquired at average values Eb/No = 2,06 dB. Whereas in multipath fading EbNo = 6.05 dB. Keywords : Low Density Parity Check Code, sparse matriks based on Approximation Lower Triangular, AWGN, Multipath Fading , decoding sum product log domain, BE

Analisa Kinerja Kode Konvolusi Pada Sistem Successive Interference Cancellation Multiuser Detection CDMA dengan Modulasi QPSK Berbasis Perangkat lunak

Pada pembuatan proyek akhir ini dilakukan analisa kinerja kode konvolusi pada sistem Successive Interference Cancellation (SIC) Multi User Detection (MUD) CDMA berbasis perangkat lunak dengan modulasi QPSK. Encoder kode konvolusi yang digunakan pada sisi transmitter memiliki struktur (2,1,2) dengan rate ½. Sedangkan pada sisi receiver dilakukan dengan metode Successive Interference Cancellation (SIC) dan dilakukan proses dekoder menggunakan algoritma viterbi. Hasilnya adalah berupa nilai bit error rate (BER) sebagai fungsi signal noise to ratio (SNR). Pada BER 10-3 kanal AWGN SIC stage 3 lebih baik 4 dB dari stage 2 dan 10,3 dB dari stage 1, untuk kanal Rayleigh fading stage 3 lebih baik 5 dB dibandingkan SIC stage 1 dan stage 2. Kinerja kode konvolusi pada sistem successive interference cancellation melalui kanal AWGN pada saat nilai 10-3 lebih baik 3,2 dB dibandingkan dengan tanpa kode konvolusi dan pada kanal Rayleigh fading pada saat SNR 15,33 dB, sedangkan sistem yang tidak menggunakan kode konvolusi belum mencapai nilai BER 10-3 sampai nilai SNR 30. Dan semakin sedikit jumlah user maka kinerja sistem akan semakin baik. KATA KUNCI : CDMA, Kode Konvolusi, Successive Interference Cancellation, Algoritma Viterb

PERBANDINGAN KINERJA RATE KODE KONVOLUSI DAN APLIKASINYA PADA SISTEM CDMA

ABSTRACK To transmite information from transmitter to receiver . Some proses is will be happen on that information. One each other is use CDMA proses. In that proses when data will be transmite the data get spreading proses after that the data get dispreading proses in receiver. In this final project we can try how the data before get spreading proses will be get Convolutional Code so after that we can get know about the effect of convolutional Code when it aplicated in CDMA sistem. In that final project we use two tipe from rate convolutional code the rate is rate 1/2 and rate 1/3 . From two rate we can analisis from the effect if we compare with BER . So we can know which the BER is better if we chose Eb/No if we use in use dB. With compare between convoluitonal code rate 1/2 and rate 1/3 we can know about the performance if wa use in CDMA system. The result of these we know rate 1/3 have good performance BER than rate 1/2 . In rate 1/2 for Eb/No 10-3 need Eb/No 11 dB and in rate 1/3 need Eb/No 10 dB. From that result we know if rate 1/3 have more good performance than rate 1/2 . Kata kunci : Convolutional Code,CDMA,BER

Analisa Kinerja Kode Konvolusi pada Sistem Successive Interference Cancellation Multiuser Detection CDMA dengan Modulasi QAM Berbasis Perangkat Lunak

Pada Proyek Akhir ini dilakukan Analisa Kinerja Kode Konvolusi pada Sistem Successive Interference Cancellation Multiuser Detection CDMA dengan Modulasi Quadrature Amplitude Modulation Berbasis Perangkat Lunak. Encoder kode konvolusi digunakan di sisi transmitter dengan rate 1/2 dan decoder di sisi receiver menggunakan algoritma viterbi. Hasil berupa kurva nilai BER terhadap fungsi SNR. Dari hasil simulasi didapatkan hasil bahwa pada sistem tanpa menggunakan kode konvolusi memiliki kinerja yang lebih baik karena sudah mencapai BER 10-3 ketika SNR 15.5 dB sedangkan sistem tanpa menggunakan kode konvolusi belum dapat mencapai nilai BER 10-3. Pada system perbandingan stage pada SIC menunjukkan bahwa penggunaan SIC 3 stage memiliki kinerja yang lebih baik 1.5 dB dibandingkan dengan jika menggunakan 1 atau 2 stage saja. Sedangkan untuk sistem dengan menggunakan 6 user memiliki kinerja yang lebih baik 9.5 dB jika dibandingkan dengan sistem yang menggunakan 10 user. Kata Kunci : BER, Convolution Code, CDMA, Quadrature Amplitude Modulation, Successive Interference Cancellation, multipath fadin

Analisa Kinerja Orthogonal Frequency Division Multiplexing Berbasis Perangkat Lunak

There are many methods to solve the needs of channel communication system and the effects of multipath fading one of them is by using the Orthogonal Division Multiplexing (OFDM) system. OFDM system is the development of Frequency Division Multiplexing (FDM). The fundamental difference of OFDM and FDM system that is located on the frequency sub-carriers, the OFDM system is allowed to sub-carriernya frequency overlapping each other so that they can save bandwidth channel communication system, and increased channel capacity. OFDM system is not only overcome the channel capacity can be improved but also can overcome effects from multipath fading. In this final project is done a analyzing the performance of OFDMbased software. From the data simulation is obtained values of Bit Error Rate (BER) will increase as levels of modulation increase or the number of M-ary increase. OFDM with Quadrature Amplitude Modulation Modulation (QAM) has a good BER compared with OFDM with Phase Shift Keying (PSK). On 10 tap Rayleigh channel OFDM with 10-QAM modulation has 1 dB better than QPSK, OFDM with 8-QAM modulation has 3 dB better than the 8-PSK, OFDM with 16-QAM modulastion has 5 dB better than the 16 - PSK, and for OFDM with 256- QAM modulation has 15 dB better than 256-PSK. Keyword : OFDM, IFFT, FFT, Cylic Prefix, Rayleigh Fadin

ANALlSA KINERJA MODULASI GAUSSIAN MINIMUM SHIFT KEYING BERBASIS PERANGKAT LUNAK

In a wireless communication system bandwidth on the spectrum efficiency of radio frequency (RF) Limited, this is a demands considerable importance. In an effort to meet these demands, then applied the method of filtering digital data signal prior to modulation. GMSK Gaussian Minimum Shift Keying or is the development of MSK, the technique eliminates sidelobe spectrum with NRZ signal by passing the Gaussian filter LPF. In this final project, analyzed how the performance of a GMSK modulator through simulations using the software CppSim and observation of the output signal. Keywords: GMSK Modulation, Frequency Carier, Gaussian filter LPF

ANALISIS KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ DAN ¾ MENGGUNAKAN 4 ANTENA MODULASI M-QAM BERBASIS PERANGKAT LUNAK

In wireless communications has one characteristic that is the phenomenon of multipath fading, it takes a technology that could make the reflection signal does not eliminate the primary signal. The use of multiple antennas at the transmitter and the receiver is expected to result in improved quality of the wireless communication service. This technique is known as MIMO (Multiple Input Multiple Output). One scheme is MIMO STBC (Space Time Block Code), which has a subclass of OSTBC (Orthogonal Space Time Block Code). The principle OSTBC is sending some signal replicas information on the independent channel fading in orthogonal signal format, so that at least one signal receiver who did not experience the worst fading. So with the process of sending data faster and more reliable. At the end of this project described the performance of OSTBC using 4 pieces with rate ½ and ¾ to resolve an issue with multipath fading in wireless communications. Here is observed the SNR (Signal To Noise Ratio) and BER (Bit Error Rate) that can be know performance. Results obtained in the form of graphs of functions of Eb / No in dB. For OSTBC rate ½ 4 QAM modulation for the amount of 4 antenna transmitter and receiver antenna gain BER 10ିଷ at SNR ± 9 dB, for 8 QAM modulation at ± 8 dB SNR for 16 QAM modulation on the SNR ± 7 dB. For OSTBC rate ¾ 4 QAM modulation amount of 4 antenna transmitter gain 4 antenna receiver BER ¾ at SNR ± 12.5 dB, for 8 QAM modulation at ± 12 dB SNR for 16 QAM modulation on the SNR ± 11 dB Keywords : Multipath fading, OSTBC, rate,MIM