{"title":"Performance Analysis of HSDPA Systems using Low-Density Parity-Check (LDPC)Coding as Compared to Turbo Coding","authors":"K. Anitha Sheela, J. Tarun Kumar","country":null,"institution":"","volume":48,"journal":"International Journal of Electronics and Communication Engineering","pagesStart":1839,"pagesEnd":1845,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/4836","abstract":"HSDPA is a new feature which is introduced in\r\nRelease-5 specifications of the 3GPP WCDMA\/UTRA standard to\r\nrealize higher speed data rate together with lower round-trip times.\r\nMoreover, the HSDPA concept offers outstanding improvement of\r\npacket throughput and also significantly reduces the packet call\r\ntransfer delay as compared to Release -99 DSCH. Till now the\r\nHSDPA system uses turbo coding which is the best coding technique\r\nto achieve the Shannon limit. However, the main drawbacks of turbo\r\ncoding are high decoding complexity and high latency which makes\r\nit unsuitable for some applications like satellite communications,\r\nsince the transmission distance itself introduces latency due to\r\nlimited speed of light. Hence in this paper it is proposed to use LDPC\r\ncoding in place of Turbo coding for HSDPA system which decreases\r\nthe latency and decoding complexity. But LDPC coding increases the\r\nEncoding complexity. Though the complexity of transmitter\r\nincreases at NodeB, the End user is at an advantage in terms of\r\nreceiver complexity and Bit- error rate. In this paper LDPC Encoder\r\nis implemented using \u201csparse parity check matrix\" H to generate a\r\ncodeword at Encoder and \u201cBelief Propagation algorithm \"for LDPC\r\ndecoding .Simulation results shows that in LDPC coding the BER\r\nsuddenly drops as the number of iterations increase with a small\r\nincrease in Eb\/No. Which is not possible in Turbo coding. Also same\r\nBER was achieved using less number of iterations and hence the\r\nlatency and receiver complexity has decreased for LDPC coding.\r\nHSDPA increases the downlink data rate within a cell to a theoretical\r\nmaximum of 14Mbps, with 2Mbps on the uplink. The changes that\r\nHSDPA enables includes better quality, more reliable and more\r\nrobust data services. In other words, while realistic data rates are\r\nonly a few Mbps, the actual quality and number of users achieved\r\nwill improve significantly.","references":null,"publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 48, 2010"}