N.Yee, J.P.M.G.Linnartz, and G.Fettweis. Multi-Carrier CDMA in Indoor Wireless Radio Networks. Proceedings PIMRC'93, Yokohama, Japan, 1993, pp.109-113.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....enables full multipath diversity that can be collected at the receiver by MRC. SS OFDM only transmits one information symbol per OFDM block, which comes at the price of considerable rate loss. To share the N subcarriers among multiple (say U ) users, multi carrier (MC) CDMA has been advocated in [22], where different users are distinguished by their signature codes c u=0 . The received vector becomes r(i) D h,u c u s u (i) w(i) 6) where D h,u and s u (i) are the corresponding diagonal channel matrix and information symbol for user u. With U 2, optimal decoding requires ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. of IEEE PIMRC, Sept. 1993, pp. 109--113.

....redundancy by using J subcarriers to transmit K symbols. In the extreme case, all the N available subcarriers can be used to transmit one symbol, which is essentially SS OFDM proposed in [4] To make up for the considerable rate loss inherent in SS OFDM, multicarrier (MC) CDMA has been proposed in [13], where different users share all the subcarriers and are distinguished by their signature codes. MUI thus appears, that needs to be suppressed by joint multiuser detection (MUD) The performance of MC CDMA is upper bounded by SS OFDM, because the latter corresponds to the best scenario where ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. of IEEE PIMRC, Sept. 1993, pp. 109-- 113.

....achieve significantly higher data rates with a wide range of coverage. In a broadband channel with an approximate 50 100 MHz bandwidth comprising many multipaths, the authors clarified that orthogonal frequency and code division multiplexing (OFCDM) which is originally based on multicarrier CDMA [3], 4] or orthogonal frequency division multiplexing (OFDM) exhibits better performance than conventional DS CDMA based wireless access in the forward link [5] 7] This is because OFCDM and OFDM mitigate the degradation due to severe multipath interference in a broadband channel using many low ....

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multi-Carrier CDMA in indoor wireless radio networks," PIMRC '93, pp. 109-113, Sept. 1993.

....an expression of the BER for BPSK modulation will be derived for an UL scenario. A comparison will be finally made in terms of BER between NCP MC CDMA schemes that use equalising receivers and CP MC CDMA schemes. II. THE CP MC CDMA TRANSMITTER The block diagram of the CP MC CDMA transmitter [2] including the mobile channel, is depicted in Figure 1. The complex symbols transmitted by user k during the signaling iteration n are first up sampled by a factor of Nc and then provide input to a FIR filter, of length No, with an IR ak (m) This operation is actually identical to the spreading ....

N. Yee, J.-P. Linnartz, G. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks", in Proceedings of the IEEE International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC'93), Yokohama, Japan, pp. 109-113, 1993.

.... with a maximum data rate above 100 Mbps using an approximate 50 to 100 MHz bandwidth [3] 5] In such a broadband channel comprising many multipaths, the authors clarified that Orthogonal Frequency and Code Division Multiplexing (OFCDM) which is originally based on Multi carrier CDMA (MC CDMA) [6], 7] or Orthogonal Frequency Division Multiplexing (OFDM) exhibits better performance than conventional DS CDMA based wireless access [3] 5] This is because OFCDM and OFDM mitigate the degradation due to severe multipath interference (MPI) in a broadband channel using many low symbol rate ....

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multi-Carrier CDMA in indoor wireless radio networks," IEEE PIMRC'93, pp. 109-113, Sept. 1993.

.... Despite big implementation challenges, like designing linear amplifiers to cope with the large Peak toAverage Power ratio of an OFDM signal, multi carrier schemes are promising and has been subject to intensive research over the years, 2 4] The earlier proposed Multi Carrier CDMA (MC CDMA) [5 7] and Multi Carrier Direct Sequence CDMA (MC DSCDMA) 8] systems spread the symbols either in the frequency or in the time direction [3] Theses schemes are illustrated in figures 1c and d. A frequency selective fading channel will scale the chips di#erently and cause correlation between the ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks, " in Proc. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Yokohama, Japan, Sept. 1993, pp. 109--113.

....The code tree upto level 3, consisting of a total of 7 codes, is shown in Figure 2. OVSF codes allow us to allocate variable spread factor codes, resulting in variable data rate allocation to the terminals, while still maintaining orthogonality. A pair of C (1) 1] 1 C (1) 11] C (2) [10] 2 C (4) 1001] C (2) 1100] C (1) 1111] C (3) 1010] 3 3 3 2 3 SF=2 SF=4 SF=1 Fig. 2. Orthogonal Variable Spreading Factor Code Tree shown up to level 3. possibly di erent length) codes in this set are orthogonal to each other except when one is derived from the other. C. ....

....1=T b at baseband, where T b is the symbol duration. This results in the subcarriers being orthogonal to each other at baseband. At the receiver, by multiplying with the particular frequency of interest and summing over a symbol duration, we can isolate the symbol component at that subcarrier [10]. MC CDMA is a combination of DS CDMA (Direct Sequence CDMA) and the OFDM (Orthogonal Frequency Division Multiaccess) techniques and inherits all the good and bad properties of its parents[9] MC CDMA transmits the same symbol over a number of parallel subcarriers, where the number of subcarriers ....

[Article contains additional citation context not shown here]

Nathan Yee, J.P. Linnartz, and G. Fettweis, Multicarrier cdma in an indoor wireless radio network, in Proc. IEEE PIMRC, Sep 1993, pp. 109113.

....pair mutually agree on a code before initiating communication. Receiver terminals are equipped with the facility to broadcast the code on which they are receiving their transmission. This is done on a broadcast channel (time slot) during the Medium Access Control layer ACK phase. If the MC CDMA[6], 7] is being used, then this can be done easily without extra hardware and without encroaching on the data transmission, as shown in [8] A CDMA system with code reuse is prone to the problem of secondary interference. Two possible situations in which such interference can occur, as observed in ....

Nathan Yee, J.P. Linnartz, and G. Fettweis, Multicarrier CDMA in an indoor wireless radio network, in Proc. IEEE PIMRC, Sep 1993, pp. 109113.

.... interference (NBI PBI) 14] FD SS, with disjoint frequency support for each subcarrier, is, in fact, the analog counterpart of digital OFDM spread spectrum technique [23] 24] and the underlying multicarrier spread spectrum (MC SS) approach for multicarrier (MC) CDMA with overlapping subcarriers [27]. By exploiting multiple carriers and a narrowband DS waveform on each subcarrier, it has been shown that multicarrier DS CDMA outperforms single carrier CDMA for wideband transmissions in the presence of narrowband interference [16] results for partial time jamming may be found in [5] ....

....devices and digital signal processing (DSP) technologies, the digital to analog (D A) and analog to digital (A D) converters are being pushed closer to the transceiver s end. A unifying digital implementation framework of many existing schemes has been developed [10] 26] which includes MC CDMA [27] and MC DS CDMA [16] as special cases. In this paper, we focus on the single user scenario where the narrowband signals are spread over a much wider bandwidth to combat narrowband interference and multipath fading. Starting from a discrete time equivalent model, we investigate the performance of ....

[Article contains additional citation context not shown here]

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. IEEE PIMRC, Sept. 1993, pp. 109--113.

....should be developed. Recently, multicarrier (MC) transmission schemes have been introduced into CDMA systems to get such advantages as bandwidth efficiency, frequency diversity, lower speed parallel type of signal processing, and interference rejection capability in high data rate transmission [4] [9] These proposed techniques can be categorized into two types, the orthogonal frequency division multiplexing (OFDM) CDMA which is a pseudo noise coded structure, and the parallel transmission of narrowband DS waveforms in the frequency domain. The MC CDMA system proposed in [7] belongs to ....

N. Yee, J. P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. PIMRC, Yokohama, Japan, Sept. 1993, pp. D1.3.1--D1.3.5.

.... [5] 9] With these advantages, multicarrier transmission schemes have been introduced into CDMA systems for high bit rate data transmission [10] 22] These proposed schemes can be categorized into two groups: the OFDM CDMA, which is a pseudonoise coded structure in the frequency domain [11], 17] and the parallel transmission of narrow band DS waveforms in the frequency domain [10] 12] 16] 18] 22] In the second group, there are two different methods combining DS spreading and multicarrier modulation. The first method is to perform multicarrier modulation on the information ....

N. Yee, J. P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," IEICE Trans. Commun., vol. E77-B, no. 7, pp. 900--904, July 1994.

.... (MC) CDMA systems have been developed and rapidly gained popularity as they capitalize on both OFDMA s resilience to MUI and direct sequence (DS) CDMA s robustness against frequency selectivity to mitigate both MUI and the inter symbol interference (ISI) caused by time dispersive channels [1, 3, 4, 10,12,16, 20]. The spread spectrum multicarrier multiple access schemes developed in [11,12,14] rely on bandwidth expanding repetition or convolutional codes for MUI elimination and mitigation of frequency selective uplink channels. But no existing MC or DS CDMA scheme guarantees (blind or not) symbol recovery ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. IEEE International Symposium on Personal, Indoor and Mobile Radio Comm., Sept.

....hand, the ability of direct sequence (DS) CDMA to exploit multipath diversity (via RAKE reception) is well documented. Capitalizing on both OFDMA s resilience to MUI and DS CDMA s robustness against time dispersiveness, multicarrier (MC) CDMA systems have been proposed to suppress both MUI and ISI [1, 2, 4, 9, 11, 20, 25]. In the uplink, the use of channel coding, in the form of repetition or convolutional codes, results in further BER improvements at the expense of complexity and bandwidth overexpansion [10, 14] However, without channel coding, symbol interleaving or assumptions on the channel nulls, there is ....

N. Yee, J-PMG. Linnartz, and G. Fettweis. Multi-carrier CDMA in indoor wireless radio networks. IEICE Transactions on Communications, E77-B(7):900--904, July 1994.

....Daffara [45] and Sandell [46] 3) OFDM CDMA: Combining OFDM transmissions with code division multiple access (CDMA) allows us to exploit the wide band channel s inherent frequency diversity by spreading each symbol across multiple subcarriers. This technique has been pioneered by Yee et al. [47], by Chouly et al. 48] and by Fettweis et al. 49] Fazel and Papke [50] investigated convolutional coding in conjunction with OFDM CDMA. Prasad and Hara [51] compared various methods of combining the two techniques, identifying three different structures, namely multicarrier CDMA (MC CDMA) ....

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. PIMRC'9S, 1993, pp. 109--113.

....of multiplying the input sequence by a discrete matrix, referred to as the shaping matrix. The entries of this matrix are 2 directly obtained from the selected set of time waveforms. The new structure of the shaped OFDM scheme is similar to that of Multi Carrier CDMA (MC CDMA) schemes [13] [14], giving the possibility to apply similar detectors. It also introduces a different approach in designing pulse shaping for OFDM and allows the system to get al..l the benefits of pulse shaping without affecting the OFDM structure. This paper is organized as follows: In section 2 the system model is ....

.... Multi Carrier CDMA Considering the expression of the transmitted sequence s k given by (7) we notice that if the shaping matrix is an orthogonal Hadamard matrix, P = a ij ] a ij = Sigma 1 p N ; 10) the sequence then becomes that of a MC CDMA signal with a total of N u = N users [13] [14] and the block diagram in Figure 2 becomes a synchronous MC CDMA transmitter. Therefore, the same signal can be obtained using the block diagram of Figure 1, with each subcarrier using the following pulse shape p m (t) N Gammam Gamma1 X i= Gammam a (i m)m e j2i t T u T (t Gamma T=2) ....

N. Yee, J. Linnartz, and G. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks," PIMRC '93, pp. 109-113, Yokohama, Japan, 1993.

....hand, the ability of direct sequence (DS) CDMA to exploit multipath diversity (via RAKE reception) is well documented. Capitalizing on both OFDMA s resilience to MUI and DS CDMA s robustness against time dispersiveness, multicarrier (MC) CDMA systems have been proposed to suppress both MUI and ISI [1, 2, 4, 9, 11, 20, 25]. In the uplink, the use of channel coding, in the form of repetition or convolutional codes, results in further BER improvements at the expense of complexity and bandwidth overexpansion [10, 14] However, without channel coding, symbol interleaving or assumptions on the channel nulls, there is ....

N. Yee, J-PMG. Linnartz, and G. Fettweis. Multi-carrier CDMA in indoor wireless radio networks. IEICE Transactions on Communications, E77-B(7):900--904, July 1994.

....code vector cm . In the sequel, we will also showhow three multicarrier schemes can be implemented digitally as special cases of GMC CDMA. With their discrete time equivalent models, it becomes clear that symbol recovery in the uplink is not always possible. Multicarrier CDMA (MC CDMA) [3, 9]: MC CDMA combines DS CDMA with OFDM modulation. For this scheme, no blocking occurs at the transmitter (i.e. K =1) and Theta m is a J Theta 1vector m (the spreading filter) The Fm matrix is no longer user dependent, and with P = J L, it is selected to be a P Theta J matrix consisting of ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. of

....for frequency management. Motivated by tradeoffs between DS CDMA and OFDMA systems, it is not surprising that in the last few years a lot of research has focused toward hybrid techniques [69] 180, chapter 11] Different approaches have been proposed including: s Multicarrier CDMA (MC CDMA) [296], 70] 40] s Multicarrier DS CDMA [53] s Multitone (MT) CDMA [264] 265] s M ary modulation for MC SS [56] However, all these techniques are not immune to MUI, and cannot cope with (perhaps unknown) multipath channels. A generalized OFDMA like scheme offering MUI suppression and allowing ....

N. Yee, J.P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," Proc. IEEE PIMRC'93, Yokohama, Japan, pp. 109-113, Sept. 1993.

.... as the data tr17IfiI14fi7 r1r r1rIfiI for wirIfiI multimedia serdia incr1)7UI Another apprer h called the MC CDMA has been pr1 osed lately to overI( the capacity limit of a DS CDMA technique due to inter chip interIN14fiI and multi user interI)I14fi in high data rta communication systems [2]. Since the MCCDMA technique is based on a combination of OFDM signaling and CDMA technique, it has the pr1 er1EI desirEI( for highdata r6P wir r6 multimediasermedi such as insensitivity tofrPN614)N( 1rPN1 e channel with a simple one tapequalizer frualize diver1E y, and capability of handling ....

.... as the number of mobilesdecres1I or as the number ofarP y elementsincr(714fi Note also that the prUUU6P14 y oferN( equation, 21) for an MC CDMA system with antennaarn y isrIP7P( to thepr1U6EU r sult der1 edfor an MC CDMA system without antenna arn y when the number ofarI y elements becomes one [2]. 3. An MC CDMA System with Antenna Array in Forward Link Using thetr1PU76 signalstrals1IE) by the base stationthr1PP for ar link to all mobiles at perfi dic inter als, mobilesriles1P) theinforUI14fi necessar for spatialpr cessing in the base station thrion the rh ere link. The base station ....

N. Yee, J.-P. Linnartz, and G. Fettweis, "MulticarrierCDMA in indoor wireless radio networks," Proc. PIMRC'93, pp.109--113, Yokohama, Sept. 1993.

....features ofOF#4E and its potentiality to improve the system performance of conventional single carrier DS CDMA under frequency selective fading environment. Some types ofOF#kE6k4m systems have been proposed. Basically there can be classified into two types of OF#kIkmPk systems [1] Copy type [2] and Serial to Parallel (S P) type [3] In the Copy type [2] which also known asOF##4 4mPk the same data rate are transmitted over a number of orthogonal subcarriers, which must be equal to the number of chips of spreading sequence, then all substreams are spread by spreading sequence in ....

....performance of conventional single carrier DS CDMA under frequency selective fading environment. Some types ofOF#kE6k4m systems have been proposed. Basically there can be classified into two types of OF#kIkmPk systems [1] Copy type [2] and Serial to Parallel (S P) type [3] In the Copy type [2], which also known asOF##4 4mPk the same data rate are transmitted over a number of orthogonal subcarriers, which must be equal to the number of chips of spreading sequence, then all substreams are spread by spreading sequence in frequency domain. In the Serial to Parallel System[4] which also ....

N. Yee, J.P. Linnartz, and G. Fettweiss, "Multicarrier CDMA in indoor wireless radio networks," Proc. PIMRC'93,p3,yN]"kHy Sep 1993.

....in [7, 8] 5. UNIFYING FRAMEWORK A number of multiuser multicarrier schemes fall under the model of Fig. 1(a) We outline some of them in this section by describing their baseband discretetime equivalent models in order to illustrate the generality of GMC CDMA. Multicarrier CDMA (MC CDMA) [3, 11]: For this multicarrier scheme, no blocking of data symbols occurs at the receiver and the first precoding matrix Theta m is a Q Theta 1 vector m (the spreading filter) The F m matrix is no longer user dependent, as it is selected to be a Q Theta Q IFFT matrix augmented either by an L ....

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. of IEEE PIMRC '93, Sept. 1993, pp. 109--13.

....systems with high data rates, Orthogonal Frequency Division Multiplexing (OFDM) has received a lot of attention in the recent few years. Despite of some advantages like simple onetap equalization, OFDM has to be combined with diversity techniques to exploit the multipath fading channel [1, 2, 3, 4, 5]. In this paper, we consider the scheme where each information symbol is spread in frequency direction by simple replication of the symbol into parallel subcarriers and additional multiplication of each subcarrier with one code chip being constant in time. This concept was first introduced as ....

N. Yee, J.-P. Linnartz, and G. Fettweis. Multi-Carrier CDMA in Indoor Wireless Radio Networks. In Proc. IEEE Int. Symp. on Personal, Indoor and Mobile Radio Communications (PIMRC), pages D1.3.1--D1.3.5, September 1993.

....fading of each subcarrier can be assumed as frequency nonselective. To achieve frequency diversity, OFDM can be combined with code division multiple access (CDMA) where the signal is spread over all subcarriers. This concept was first introduced as OFDMCDMA or also as multi carrier (MC )CDMA by [1, 2] and is also called MC spread spectrum (MC SS) In the recent few years, most publications dealing with MC SS have been focused on classical modulation schemes such as BPSK [3, 4] and several maximum likelihood (ML) decoding strategies were proposed [5, 6] Instead of using classical modulation ....

N. Yee, J.-P. Linnartz, and G. Fettweis. Multi-Carrier CDMA in Indoor Wireless Radio Networks. In Proc. IEEE Int. Symp. on Personal, Indoor and Mobile Radio Commun. (PIMRC'93), pages D1.3.1--D1.3.5, September 1993.

....functions. This fact leads to an asynchronous situation involving the use of PN sequences, which results in higher MAI . Furthermore, maximum ratio combining (MRC) detection strategy is applied, being proper to reduce the interferences caused by the frequency selective fading of the channel [7]. Ideal channel estimation is assumed and no channel coding is involved. In contrast with single carrier transmission, a MC CDMA scheme yields a frequency resolution by dividing the available bandwidth into a finite number of subbands. The idea behind the application of M ary Walsh modulation is ....

N. Yee, J.-P. Linnartz, and G. Fettweis. Multi-Carrier CDMA in Indoor Wireless Radio Networks. In Proc. IEICE Transaction on Communications, volume E77B7, No.7, Japan, July 1994.

No context found.

N. Yee, J. P. Linnartz and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," Proceedings PIMRC '93, Yokohama, Japan, 1993, pp. 109-113.

No context found.

N. Yee, J.P. Linnartz, and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. IEEE PIMRC `93, Yokohama, Japan, Sept. 9-11, 1993, pp. 109-103.

No context found.

N. Yee, J. P. Linnartz, and G. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks," Proc. IEEE PIMRC'93, pp. 109--113, Sept. 1993.

No context found.

N. Yee, J. P. Linnartz and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," Proceedings PIMRC '93, Yokohama, Japan, 1993, pp. 109-113.

....The signal at the receiver is (3) with the added white Gaussian noise (AWGN) with variance . The CIRs for all users are assumed to be perfectly known to the receiver. B. Modulation Scheme: Multicarrier Spread Spectrum In the early 1990s, multicarrier spread spectrum (MC SS) was introduced [14] [15]. A detailed state of the art overview about MC SS is found in [16] and [17] Because of MC SSs suitability for low cost terminals [18] 19] it is used as a spreadspectrum technique in this paper. The spreading signal is given by and (4) Hence, the spreading signal is determined by the ....

N. Yee, J. P. Linnartz, and G. P. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks," in Proc. IEEE PIMRC, Yokohama, Japan, 1993, pp. 109--113.

....and implementation issues. I. Motivation In the early nineties, the breakthrough for DS SS CDMA came with the commercialization of IS 95 as well as for OFDM with xDSL. Therefore most research e#ort is concentrated on combining the advantages of both techniques into a new one. One approach [1] called multi carrier spread spectrum (MC SS) has the goal of designing a spread spectrum system dual to DS SS in the sense that DS SS time domain operations are MC SS frequency domain operations and vice versa [2] That approach includes also the proposal [3] although the authors did not call ....

N. Yee, J.-P. Linnartz, and G. P. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. 4th IEEE Int. Symp. Personal, Indoor and Mobile Radio Commun. , pp. 109--113, 1993.

....outside the bands. Furthermore, the specifications allow that several wireless systems work in the same ISM band. Hence, such systems have to be resistant against unknown jammers and transmit at a low average power. Therefore, they require MC SS is a new spread spectrum modulation technique [1], 2] with better spectral properties than DS SS and very good correlation properties in both time and frequency domain [3] The high number of operations to compress the received signal is a challenging task of spreadspectrum systems. Using SAW filters as fast analog correlators is an attractive ....

N. Yee, J.-P. Linnartz, and G. P. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. of the 4th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, (Yokohama), pp. 109--113, 1993.

....interference cancellation, respectively. Furthermore, two proposals considering the code dependent cross correlation function will be given to modify this multiple access scheme so that the uplink performance of such a system is enhanced without additional hardware cost. I. INTRODUCTION In [1] and [2] the new modulation techniques called multi carrier spreadspectrum (MC SS) was introduced. To generate the wideband code signal using a weighted trigonometric sum is the basic idea of MC SS. This kind of spread spectrum signal has more degrees of freedom to influence system ....

....In [3] it was shown that MC SS has better spectral properties then DS SS and also a good auto correlation behavior. The latter allows time domain equalization like a matched filter (MF) or a RAKE receiver instead of frequency domain equalization that was proposed in first publications about MC SS [1] and [2] In [4] it is proposed to de spread the incoming signal with an fast analog surface acoustic wave (SAW) device to reduce the complexity of the MC SS receiver. In a multi user system, every user should work with an identical SAW filter to lower the costs. That means that all users have ....

N. Yee, J.-P. Linnartz, and G. P. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. of the 4th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, pp. 109--113, 1993.

....license free ISM bands, where spread spectrum techniques are required through the national communications commissions, direct sequence spreadspectrum (DS SS) systems are candidates for such applications with low signal processing complexity. In this paper MC SS, introduced in the early nineties [1], 2] is investigated. For MC SS a rectangularshaped spectrum is achieved through the modulation principle. Hence additional pulse shaping can be avoided. This is a significant implementation advantage compared to DS SS based on binary pseudo random short codes. The typical multi carrier problem ....

N. Yee, J.-P. Linnartz, and G. P. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. 4th IEEE Int. Symp. Personal, Indoor and Mobile Radio Commun. , pp. 109--113, 1993.

....signal consists of the sum of the outputs of these branches. For F = 1, this scheme is similar to performing Orthogonal Frequency Division Multiplexing (OFDM) 3] on a Direct Sequence spread spectrum signal [4] Recently, there has been a growing interest on idea of combining OFDM and DS CDMA [5] [6] 7] 8] 9] Modern DSP methods make the implementation of MC CDMA feasible and attractive. With F = 1, the transmit bandwidth is minimized. However, larger values of F may be desired to further increase the transmit bandwidth, i.e. to achieve a larger frequency diversity gain, without ....

N. Yee, J.P. Linnartz, and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," in Proc. IEEE PIMRC `93, Yokohama, Japan, Sept. 9-11, 1993, pp. 109-103.

....modulation multiple access scheme in the downlink of an indoor wireless Rician fading channel. The performance of a controlled equalization technique that attempts to restore the orthogonality between users is evaluated. 1. Introduction This paper will extend on the results of a previous paper [1] involving the analysis of a new spread spectrum transmission method called MC CDMA. MC CDMA [1,2,3] addresses the issue of how to spread the signal bandwidth without increasing the adverse effects of the delay spread, which is a measure of the length of the channel impulse response. With MC CDMA, ....

....The performance of a controlled equalization technique that attempts to restore the orthogonality between users is evaluated. 1. Introduction This paper will extend on the results of a previous paper [1] involving the analysis of a new spread spectrum transmission method called MC CDMA. MC CDMA [1,2,3] addresses the issue of how to spread the signal bandwidth without increasing the adverse effects of the delay spread, which is a measure of the length of the channel impulse response. With MC CDMA, a data symbol is transmitted over N narrowband subcarriers where each subcarrier is modulated by ....

[Article contains additional citation context not shown here]

N. Yee, J. P. Linnartz and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," Proceedings PIMRC '93, Yokohama, Japan, 1993, pp. 109-113.

....Simulation results are also presented on the effect of correlated fading (in the frequency domain) at the subcarriers. I. Introduction In an earlier paper, the authors discussed the utilization of MC CDMA as a digital modulation and multiple access technique in an indoor wireless environment [1]. Due to its special signal structure, MC CDMA signals will not experience significant linear distortion in fading channels where the symbol duration, is much larger than the delay spread, With orthogonal MC CDMA [2] each data symbol is simultaneously transmitted at N binary phase ....

.... not be confused with transmitting multiple DS CDMA signals at different frequencies as done so in [4] Note that the signal structure of MCCDMA is similar to that of Orthogonal Frequency Divi T b T d F T b X cos(2pf c t 2pF(N 1)t T b ) X cos(2pf c t 2pFt Tb) X cos(2pf c t) X c m [N 1] X c m [1] X c m [0] a m [k] S Fig. 1 Transmitter model of the mth user s m (t) sion Multiplexing (OFDM) 5] but the manner in which the signals are used is very different. While the general shape of the each individual subcarrier will not experience significant linear distortion after ....

[Article contains additional citation context not shown here]

N. Yee, J. P. Linnartz and G. Fettweis, "Multi-Carrier CDMA in Indoor Wireless Radio Networks," Proceedings PIMRC '93, Yokohama, Japan, 1993, pp. 109-113.

No context found.

N.Yee, J.P.M.G.Linnartz, and G.Fettweis. Multi-Carrier CDMA in Indoor Wireless Radio Networks. Proceedings PIMRC'93, Yokohama, Japan, 1993, pp.109-113.

No context found.

N. Yee, J.P. Linnarz, G. Fettweis, "Multi-Carrier CDMA in indoor wireless radio networks," in IEEE international symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '93), September 1993, pp. 109--113.

No context found.

N. Yee, J.P. Linnartz and G. Fettweis: "Multicarrier CDMA in indoor wireless radio networks, " Proc. of PIMRC'93, Yokohama, pp. 109-113, September 1993.

No context found.

N. Yee, J.P. Linnartz, and G. Fettweis. Multi--Carrier CDMA in Indoor Wireless Radio Networks. In proceedings of IEEE PIMRC, pages 109--

No context found.

N. Yee, J.P. Linnartz, and G. Fettweis. Multi--Carrier CDMA in Indoor Wireless Radio Networks. In proceedings of IEEE PIMRC, pages 109--113, Yokohama, Japan, September 1993.

No context found.

N. Yee, J.P. Linnartz, and G. Fettweis. Multi--Carrier CDMA in Indoor Wireless Radio Networks. In proceedings of IEEE PIMRC, pages 109--113, Yokohama, Japan, September 1993.

No context found.

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proceedings of PIMRC. September 1993, pp. 109--113, IEEE.

No context found.

Yee N., Linnartz J.-P., Fettweis G. "Multi-Carrier CDMA in Indoor Wireless Radio Networks". In Proc. IEICE Transaction on Communications, volume E77-B7, No. 7, Japan. 1996.

No context found.

N. Yee, J. P. Linnartz, and G. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks," in Proc. Personal, Indoor, Mobile Radio Communications Conf., Sept. 1993, pp. 109--113.

No context found.

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multi-carrier CDMA in indoor wireless radio networks," in Proc. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Yokohama, Japan, Sept. 1993, pp. 109--113.

No context found.

N. Yee, J.-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. IEEE PIMRC, Sept. 1993, pp. 109--113.

No context found.

N. Yee, J-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," in Proc. IEEE PIMRC,Sept. 1993, pp. 109--113.

No context found.

N. Yee, J.P. Linnartz, G. Fettweis, "Multicarrier CDMA in Indoor Wireless Radio Networks", Proc. PIMRC'93, Yokohama, Japan, 1993, pp. 109-113

No context found.

N. Yee, J.P. Linnartz, G. Fettweis, "Multicarrier CDMA in Indoor Wireless Radio Networks", Proc. PIMRC'93, Yokohama, Japan, 1993, pp. 109-113

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