Fig. 3 depicts the basic block diagram of the implemented W-CDMA receiver. The properties of the communication streams between the processes are listed in Table 2, where every chip or coefficient is represented by 8 bits. For example, the total communication bandwidth for processing 4 RAKE fingers with a spreading factor (SF) of 4 is 320 Mbit/s.
3.3. Common Characteristics
Analyzing the common characteristics of the three wireless applications we made the following observations:
• The applications have a fixed amount of processing per data sample (manifest loops). This is typically found in wireless baseband processing and audio and video filtering. It does not apply for audio and video compression, where the amount of processing is data dependent (non-manifest).
• Input data arrives at a fixed rate, which cause periodic data transfers between the successive processing blocks.
• We have semi-static life-time of a communication stream, which means a stream is fixed for a relatively long time. To describe the network traffic in a system, we adopt the notation used in [19]. According to the type of services required, the following types of traffic can be distinguished in the network:
• GT (guaranteed throughput) this is the part of the traffic for which the network has to give real-time guarantees (i.e. guaranteed bandwidth, bounded latency).
• BE (best effort) this is the part of the traffic for which the network guarantees only fairness but does not give any bandwidth and timing guarantees.
We observed that in the described applications the majority of the data streams through the successive processes. This continuous flow of data needs guaranteed throughput, because the front-end is not allowed to drop data. Depending on the standard we can use block-based communication (OFDM) or have to use streaming (UMTS) because the blocks get too large. If we compare the required bandwidth between the processes of the different applications this varies widely from several kbit/s (DRM) up to more than 0.5 Gbit/s (HiperLAN/2). Beside the main-stream of the communication we foresee a minor part (assumed to be less then 5%) of best effort communication e.g. control, interrupts and configuration data. This communication can have more relaxed requirements for the network and hence can use the best effort services.
Fig. 3 depicts the basic block diagram of the implemented W-CDMA receiver. The properties of the communication streams between the processes are listed in Table 2, where every chip or coefficient is represented by 8 bits. For example, the total communication bandwidth for processing 4 RAKE fingers with a spreading factor (SF) of 4 is 320 Mbit/s.
3.3. Common Characteristics
Analyzing the common characteristics of the three wireless applications we made the following observations:
• The applications have a fixed amount of processing per data sample (manifest loops). This is typically found in wireless baseband processing and audio and video filtering. It does not apply for audio and video compression, where the amount of processing is data dependent (non-manifest).
• Input data arrives at a fixed rate, which cause periodic data transfers between the successive processing blocks.
• We have semi-static life-time of a communication stream, which means a stream is fixed for a relatively long time. To describe the network traffic in a system, we adopt the notation used in [19]. According to the type of services required, the following types of traffic can be distinguished in the network:
• GT (guaranteed throughput) this is the part of the traffic for which the network has to give real-time guarantees (i.e. guaranteed bandwidth, bounded latency).
• BE (best effort) this is the part of the traffic for which the network guarantees only fairness but does not give any bandwidth and timing guarantees.
We observed that in the described applications the majority of the data streams through the successive processes. This continuous flow of data needs guaranteed throughput, because the front-end is not allowed to drop data. Depending on the standard we can use block-based communication (OFDM) or have to use streaming (UMTS) because the blocks get too large. If we compare the required bandwidth between the processes of the different applications this varies widely from several kbit/s (DRM) up to more than 0.5 Gbit/s (HiperLAN/2). Beside the main-stream of the communication we foresee a minor part (assumed to be less then 5%) of best effort communication e.g. control, interrupts and configuration data. This communication can have more relaxed requirements for the network and hence can use the best effort services.
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