ANALISIS PERFORMANSI DIFFERENTIAL SPACE TIME BLOCK CODE PADA SISTEM WCDMA

ABSTRAKSI: WCDMA adalah suatu sistem komunikasi wireless, merupakan salah satu teknologi selular generasi ke-3 (3G) yang dapat memberikan layanan dengan bit rate yang tinggi. Sehingga tidak hanya paket suara dan data tetapi dimungkinkan pula gambar dan video dengan kualitas tinggi ditransmisikan. Sistem WCDMA digunakan untuk memenuhi kebutuhan lebar pita frekuensi dan dapat memberikan data rate hingga 2 Mbps.Tetapi terdapat kendala utama untuk menerapkan sistem komunikasi wireless tersebut, kendala tersebut adalah performansi sinyal yang mengalami penurunan akibat terjadinya fading. Beberapa penelitian menyatakan bahwa teknik multiple input multiple output (MIMO) dapat meningkatkan performansi sistem komunikasi wireless yang dalam hal ini adalah sistem komunikasi WCDMA.Hasil analisis yang telah dilakukan dari sistem WCDMA dengan menggunakan MIMO DSTBC adalah jauh lebih baik terhadap sistem WCDMA dengan SISO. Untuk mencapai BER 10-4 sistem WCDMA yang menggunakan MIMO membutuhkan Eb/No 9,6 dB dalam kondisi 1 user dan user bergerak dengan kecepatan 3 km/jam. Sedangkan untuk sistem WCDMA tanpa menggunakan MIMO DSTBC membutuhkan Eb/No 19,5 dB untuk kondisi yang sama. Performansi sistem WCDMA menggunakan MIMO DSTBC juga akan mengalami penurunan seiring dengan pertambahan jumlah user dan pertambahan kecepatan bergerak user.Kata Kunci : MIMO, DSTBC, WCDMAABSTRACT: WCDMA is a wireless communication system, cellular technology is one of the 3rd generation (3G) which can provide services with high bit rate. So not only voice and data packets but it is also possible pictures and video with high quality transmission. WCDMA system is used to meet the needs of bandwidth and can provide data rates of up to 2 Mbps.But there are major obstacles to implementing a wireless communication system, the constraint is that the signal decreased performance due to fading. Some studies claim that the technique of multiple input multiple output (MIMO) can increase the performance of wireless communication system in this case is a WCDMA communication system.The result of the analysis was done by using MIMO DSTBC in system WCDMA is much better against the WCDMA system with SISO. In order to reach the BER 10-4 WCDMA systems that use MIMO Eb/No required 9.6 dB in conditions of a user and a user moving at 3 km/hour. As for the WCDMA system without using MIMO DSTBC 19.5 dB Eb/No required for the same condition. WCDMA system performance using MIMO DSTBC also be decreased in line with the number of users and increase the speed of moving user.Keyword: MIMO,DSTBC,WCDM

Geometrical relations between space time block code designs and complexity reduction

In this work, the geometric relation between space time block code design for the coherent channel and its non-coherent counterpart is exploited to get an analogue of the information theoretic inequality $I(X;S)\le I((X,H);S)$ in terms of diversity. It provides a lower bound on the performance of non-coherent codes when used in coherent scenarios. This leads in turn to a code design decomposition result splitting coherent code design into two complexity reduced sub tasks. Moreover a geometrical criterion for high performance space time code design is derived.Comment: final version, 11 pages, two-colum

Distributed MIMO coding scheme with low decoding complexity for future mobile TV broadcasting

A novel distributed space-time block code (STBC) for the next generation mobile TV broadcasting is proposed. The new code provides efficient performance within a wide range of power imbalance showing strong adaptivity to the single frequency network (SFN) broadcasting deployments. The new code outperforms existing STBCs with equivalent decoding complexity and approaches those with much higher complexities

Space time block code classification for MIMO signals exploiting cyclostationarity

Blind and noncooperative identification of the transmission parameters of unknown communication signals has been employed both in military and civilian applications. Multiple-Input-Multiple-Output (MIMO) transmission systems emerging in the last decade pose new challenges to the signal identification systems, one of which is the identification of the Space-Time Block Code (STBC) used in the transmission. In this work, we present a novel STBC classification algorithm that exploits the joint wide sense cyclostationary characteristics of the coded transmit signals as discriminating features. Compared to existing algorithms, the proposed method can discriminate between a large number of different STBCs

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