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Abstrak :
Sinyal yang diterima dari kanal komunikasi dengan modulasi M-QAM dapat berubah karena munculnya sejumlah bit yang salah (error). penyebab terjadinya bit error dapat berupa interferensi, seperti Rayleigh fading serta noise, seperti additive white gaussian noise (AWGN). pengurangan bit error pada modulasi M-QAM dapat digunakan dengan teknik spatial multiplexing disisi pengirim dan metode pendeteksian dan penerimaan sinyal di sisi penerima. terdapat beberapa penelitian yang dilakukan sebelumnya mengenai penerapan spatial multiplexing di sisi pengirim dan metode pendeteksian dan penerimaan sinyal di sisi penerima, seperti penelitian pada komunikasi CDMA dengan metode OSIC, ZF dan Maximum Likelihood. selain itu, terdapat penelitian tentang MMSE dan penelitian mengenai penerapan metode ZF-SIC pada modulasi BPSK. Permasalahan yang kemudian dihadapi dan menjadi pokok bahasan dalam penulisan tesis ini adalah bagaimana memaksimalkan pengurangan bit error hingga 10-4 atau mendekati 0 agar sinyal yang diterima dapat Mediterranean kembali dengan benar. untuk itu dalam tesis ini diusulkan penggunaan teknik spatial multiplexing dengan metode pembatalan atau penekanan terus menerus sinyal interferensi yang terdapat pada sinyal yang diterima yang diistilahkan dengan succesisive interference cancellation (SIC) pada metode ZF, MMSE, dan maximum likelihood serta lebih dimaksimalkan dengan menambahkan metode pemilihan sinyal gangguan terberat MRC.

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The signal received from the communication channel with M-QAM modulation can change due to the appearance of a number of wrong bits (error). the cause of bit error can be interference, such as Rayleigh fading and noise, such as additive white gaussian noise (AWGN). bit error reduction in M-QAM modulation can be used with the spatial multiplexing technique on the sending side and the method of detecting and receiving signals on the receiving side. There have been several studies conducted previously regarding the application of spatial multiplexing on the sending side and the method of detecting and receiving signals on the receiving side, such as research on CDMA communication with OSIC, ZF and Maximum Likelihood methods. In addition, there are research on MMSE and research on the application of the ZF-SIC method on BPSK modulation. The problem that is then faced and the subject of the discussion in writing this thesis is how to maximize the reduction of bit error up to 10-4 or close to 0 so that the signal received by Mediterranean can return correctly. Therefore, this thesis proposes the use of spatial multiplexing techniques by continuously canceling or suppressing the interference signals found on signals received which are termed as successful interference cancellation (SIC) in the ZF, MMSE, and maximum likelihood methods and more maximized by adding selection methods. MRC's heaviest signal interference.

Abstrak :
Teknologi dalam bidang komunikasi nirkabel dalam kurun waktu terakhir menunjukkan perkembangan yang sangat pesat. Perkembangan tersebut mengarah kepada pemenuhan akan kebutuhan kapasitas yang tinggi, serta penggunaan bandwidth yang efisien dan kemampuan dalam menghadapi gangguan selama transmisi yang berujung pada minimnya eror selama pentransmisian data. Salah satu teknologi yang dapat memenuhi semua kebutuhan diatas adalah teknologi MIMO OFDM. Pada skripsi ini, disimulasikan dan dianalisis teknik MIMO OFDM dengan menggunakan teknik Spatial Multiplexing dalam pentransmisian datanya. Pemodelan kanal yang digunakan dalam simulasi ini berbasiskan operasi Singular Value Decomposition. Performansi sistem dalam simulasi ini dinyatakan dengan korespondensi Bit Error Rate (BER), Kapasitas Kanal dan Throughput terhadap Eb/No. Performansi sistem dilihat dengan tiga jenis modulasi, yaitu QPSK, 16 QAM dan 64 QAM. Unjuk kerja keseluruhan system divariasikan dengan jenis Error Control Coding (ECC) yang digunakan, dimana pada simulasi ini, terdapat tiga jenis ECC dengan coderate yang berbeda-beda. Selain itu, user dalam simulasi ini terdiri atas dua keadaan, yaitu user diam (v = 0 m/s) dan user bergerak (v = 10 m/s). Hasil simulasi menunjukkan bahwa unjuk kerja sistem makin baik dengan menggunakan Eb/No yang tinggi. Hal ini dilihat dari grafik BER, Kapasitas kanal, throughput dan juga sinyal konstelasi yang dihasilkan. Selain itu, dari hasil simulasi, diketahui unjuk kerja sistem paling baik didapatkan dengan menggunakan coderate 1/3.

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In recent years, wireless technology development shown rapid increasing. The development lead to fulfilled high capacity needs, using efficiently of bandwidth and ability to protect data from noise and minimizing error. Technology that suited with such conditions is MIMO OFDM. In this undergraduate thesis, simulation and analysis of spatial multiplexing MIMO OFDM technique is proposed. Channel modeling that used in this simulation based on Singular Value Decomposition. The evaluation of system performance is proposed to Bit Error Rate (BER), Channel Capacity and Throughput parameter toward Eb/No value. Three type of modulation, that are QPSK, 16-QAM and 64-QAM are used in this simulation. For whole system performance, three type Error Control Coding is used in this simulation with different coderate value. Beside that, there are two user condition in this simulation, that are idle user (v = 0 m/s) and mobile user (v = 10 m/s). The simulation results show that system performance with high Eb/No value is most better. This condition is shown for BER, channel capacity, throughput and signal space graph. In addition, we can see the performance with coderate 1/3 is also better than other coderate values.

Abstrak :
One of service demand in wireless communication through air is service that base on multimedia with big capacity, high velocity, flexible , and small error. Nevertheless , known that the availability of bandwidth is limited, besides, the big bandwith can cause selective fading. Adaptive MIMO Switch (AMS) and adaptive Modulation (AM) technique are implemented to handle this problem. The principle of AMS technique is switching between Space Time Block Code (STBC) and Spatial Multiplexing (SM). While adaptive modulation is to change signal constellation (mapper) that used. AMS technique and adaptive modulation works due to feedback contains Channel State Information that represented with EB/No parameter. Coalition from both adaptive technique, hopefully can upgrade data rate with guarantee the qualities is still well-kept. In this research, AMS technique and adaptive modulation implemented in MIMO-OFDM mobile WiMAX (IEEE 802, 16e) system. The result of this research, MIMO OFDM system use AM+AMS give the performance improvement equal to kurang lebih 0,5 (data rate) and kurang lebih 1,5 dB (gain) to AM or AMS.

Abstrak :
Multiple output (MIMO) uses multiple transmit antenna and multiple receive antenna which offer better system performance and capacity in multipath fading channel....