space division multiple access in mobile communication

... used in a reference subchannel in a reference cell are distributed in different subchannels in the reuse cells The subcarriers used in a subchannel in a certain cell are unlikely to be repeated in ... MAPPING FROM SUBCARRIERSUSE OF OFDMA IN WIMAX AND LTE Subcarriers are the smallest granular units in the frequency domain, OFDM symbol duration is the smallest granular unit in the time domain in ... University Orthogonal Frequency Division Multiple Access in WiMAX and LTE: A Comparison Group 4 – Trang 2 INTRODUCTION USE OF OFDMA IN WIMAX AND LTE  NETWORK ENTRY STEPS IN WIMAX AND LTE  PERFORMANCE

Ngày tải lên: 24/07/2015, 22:26

... cập nhật các thông tin này sử dụng các bản tin tin cậy được định nghĩa theo tiêu chuẩn Dựa trên điều này, trạm gốc sẽ chọn 2 bin trong một trong số các băng và phân bố những bin như vậy cho 3 ký ... kề nhau được sắp xếp trong một nhóm, được gọi là các bin, như trong hình 5 Mỗi bin có 8 sóng mang dữ liệu và một sóng điều khiển, và 4 bin liền kề thì được nhóm vào một band Người dùng gửi dữ ... fading lựa chọn, [4] Ngoài ra, tần số đa dạng và kênh thông tin phản hồi có thể được sử dụng hiệu quả để cải thiện sức mạnh và thông lượng [4] Do đó, (OFDM) được ưu tiên trong hệ thống thông tin

Ngày tải lên: 24/07/2015, 22:27

... phaseshift keying (QPSK) Sophisticated multiple access technology like frequencydivision multiple access (FDMA), time division multiple access (TDMA) andcode division multiple access (CDMA) also gained ... multiplexing (OFDM) air interface were chosen [8] In the downlink,the popular orthogonal frequency division multiple access (OFDMA) is chosenwhile single carrier frequency division multiple access ... System for Mobile CommunicationsICI Inter-Cell Interference IFDMA Interleaved Frequency Division Multiple AccessLAP Linear Assignment Problem LLR Log Likelihood Ratio LMMSE Linear Minimum Mean

Ngày tải lên: 08/09/2015, 18:24

... signal-to-noise power ratio MAI multiple access interference TDMA time division multiple access MF matched filtering WiMAX worldwide interoperability microwave access Trang 10Summary In current broadband ... shift keying FFT fast Fourier transform SDMA space division multiple access ICI inter-carrier interference SER symbol error rate IFFT inverse fast Fourier transform SIC successive interference ... Interference Suppression in OFDMA Uplink 9 1.4 Outline 12 Chapter 2 Inter-Carrier Interference in OFDMA System Uplink 13 2.1 Frequency Asynchronism and ICI in OFDMA Uplink 13 2.2 A Review

Ngày tải lên: 14/09/2015, 14:03

... sharing of a single frequency band and time slot The first principle that we will discuss is interference averaging Recall that in-band interference is inevitable in all wireless systems In TDMA/FDMA ... is spreading gain The despreading process mitigates the interference that any one signal causes to another signal As a result, in CDMA, we increase the number of interfering signals in exchange ... cellular CDMA systems MULTIPLE ACCESS In this section, we will discuss four key principles of CDMA systems, particularly cellular systems: interference averaging, statistical multiplexing, universal

Ngày tải lên: 07/08/2014, 21:20

... area Increasing the number of users in the system increases the uplink interference, which, if a target Eb /I0is to be maintained, requires an increase in the mobile transmit power However, the mobile ... By inserting values, we can determine the expected value through numerical integration For example, forκ = 4, ν = 3/8, andσ = 8dB, we obtain [42] E  I P  Trang 490 CODE DIVISION MULTIPLE ACCESS ... (3.44) and summing overϕ i, we have the constraint K i=1 ϕ i ≤ β B T /R b (Eb /I0)req − K i=1  N P T i Trang 692 CODE DIVISION MULTIPLE ACCESS (CDMA)Defining the right-hand side of the inequality

Ngày tải lên: 07/08/2014, 21:20

... control. Trang 4CELLULAR CODE DIVISION MULTIPLE ACCESS 109to the system, the admission control process examines the increase in cell interference at the current load If the new interference level exceeds ... communicating with the strongest base station in its view In classic hard hand-off techniques, the hysteresis effect ensures that a mobile does not ping-pong between base stations However, in doing ... centralized systems where all uplink transmissions are multipoint-to-point and all downlink transmissions are to-multipoint, distributed networks have many point-to-point connections Packet radio

Ngày tải lên: 07/08/2014, 21:20

... spreading codes We arbitrarily examine the output of a filter matched to the kth user’s spreading waveform during the first bit interval (assuming perfect carrier and PN code phase tracking) Assuming ... illustrated in Figure 5.3 where the linear transformation is performed on the despread symbolsand the matched filter is defined in equation (5.3) However, since dispreading is a linearoperation, the linear ... differentialdetection The performance is again invariant to the interfering powers, thus obtaining near-far resistance Additionally the receiver requires no phase tracking, assuming that the phase isconstant

Ngày tải lên: 07/08/2014, 21:20

... (5.71) where i represents the index summing over all interfering signals. Again, the cancellation can be done before or after despreading. Further, assuming a matched filter in the first stage ˆ r (0) ... quickly in the presence of... presence of multi -access interference If a detector achieves equality in terms of the effective energy, we can interpret this as perfectly eliminating the multi -access ... approaches infinity, the linear PIC detector approaches the decorrelating detector. Additionally, one can view linear PIC as an implementation of Jacobi iterations for solving linear systems [116]. Interestingly,

Ngày tải lên: 07/08/2014, 21:20

... Chương 1: Giới thiệu 1.1 Công nghệ WCDMA và tình trạng triển khai WCDMA(wideband code division multiple access) là chuẩn liên lạc 3G song hành cùng với chuẩn GSM WCDMA là công nghệ nền tảng cho ... hóa HSPA, HSDPA HSPA (High-Speed Packet Access: Truy cập tốc độ cao) là một công nghệ truyền dẫn không dây đang được ứng dụng cho các thiết bị thông tin di động Hiện HSPA đã có hơn 130 mạng đang ... độ cao) và HS-PDSCH (High Speed Downlink Shared Channel – kênh vật lý chia sẻ đường xuống tốc độ cao) Kênh HS-SCCH thông báo cho người sử dụng về thông tin dữ liệu sẽ được gửi vào các cổng HS-

Ngày tải lên: 02/06/2015, 17:26

... retain existing customers by heightening customer loyalty and customer value 2.2 Hanoi mobile communication services In 2012, there were six providers about mobile communication service in Hanoi ... in mobile communication service market in Hanoi area Trang 8Figure 5: The proposed model for mobile communication service in Hanoi Source: the experimental model of customer loyalty in the communication ... and the symptoms of a market in transition are driving the industry’s restructuring efforts and intensifying competition between companies Mobile carriers are coming to a full realization of

Ngày tải lên: 09/05/2016, 16:44

... services provider in the brand name MobiFone, marking the beginning momentum of the mobile telephony industry in Vietnam MobiFone specializes in building, developing network and providing mobile telephony ... in 100% of provinces and cities After 7 years, in June 2006, VinaPhone was once again the first mobile network to cover service in 100% of districts nationwide, including districts in mountainous ... aims to provide practical information for administrators, new service providers who want to join or maintain their position in the mobile communication service market Finally, the dissertation

Ngày tải lên: 02/10/2017, 09:00

... region should increase linearly in each dimension as ρ increases lin- early in dB. As a result, we would also expect the outage ca- pacity region to increase linearly in each dimension as ρ in- creases. ... since one mobile may transmit at any time. A tighter inner bound may be obtained by allowing the two mobiles to transmit si- multaneously, but without the coordinating virtual central processing ... Signal Processing 2004:9, 1288–1298 c  2004 Hindawi Publishing Corporation Bounds on the Outage-Constrained Capacity Region of Space- Division Multiple- Access Radio Systems Haipeng Jin Center for...

Ngày tải lên: 23/06/2014, 01:20

... mobility. Terminals moving fast in a dense network would necessitate a lot of cell updates, increasing the RACH load, but would then need to be paged in multiple cells in case of downlink-originated ... not retained, and to allow reordering to be done for single packet streams the reordering functionality needs to be combined with macro-diversity combining in MAC-es. Thus, the new MAC-es in- sequence ... rate of 384 kbps both in downlink and in uplink. The initial terminals and networks were limited to 64–128 kbps in uplink while the latest products provide 384-kbps uplink. 1.2 HSPA standardization...

Ngày tải lên: 01/06/2014, 09:38

... computational model inspired by evolution. It represents feasible solutions in terms of individuals with genomes, and determines which individuals could survive in a certain criterion formulated ... planning. In [2], a binary string representation, the classic representation method of genetic algorithm, is applied. That is, candidate solutions are encoded as chromosome-like bit strings. In ... to explain how the GA works. According to the schema theo- rem, short, low-order, and above-average schemata receive exponentially increasing trials in subsequent generations. This proves that the individuals...

Ngày tải lên: 21/06/2014, 22:20

... The values in the table have been determined for a solution using turbo decoding and they do not include chip-le vel decoding and symbol level combining that further increase the processing needs. The ... anything in between 1-2 cycle instruction set extensions and peripheral devices executing thousands of cycles can result in grossly inefficient software. If the interrupt latency in the operating ... hardware interrupt 5, 6 = interrupt service and acknowledge interrupt to HW 9, 10 = high-priority running due to interrupt 1, 12 = interrupted low-priority task Figure 6: Controlling an accelerator interfaced...

Ngày tải lên: 22/06/2014, 19:20

... estimation schemes suitable for interleave -division multiple access (IDMA) systems are presented. Training and data are superimposed. Training-based and semiblind linear channel estimators are derived ... “Adaptive interleave -division multiple access a potential air interface for 4G bearer ser- vices and wireless LANs,” in Proceedings of the 1st IFIP Inter- national Conference on Wireless and Optical Communications Networks ... “Adaptive 4G up- link proposal based on interleave -division multiple access, ” in Proceedings of General Assembly of International Union of Radio Science (URSI ’05), New Delhi, India, October 2005. [12]...

Ngày tải lên: 22/06/2014, 23:20