Examples of Communication Systems/Radio Interface - Revision history

Guenter at 16:48, 20 February 2023

2023-02-20T16:48:52Z

Guenter at 16:24, 11 February 2023

2023-02-11T16:24:49Z

Hwang at 18:43, 6 February 2023

2023-02-06T18:43:47Z

Hwang at 18:43, 6 February 2023

2023-02-06T18:43:12Z

Hwang at 18:42, 6 February 2023

2023-02-06T18:42:45Z

Hwang at 18:41, 6 February 2023

2023-02-06T18:41:31Z

Hwang at 18:36, 6 February 2023

2023-02-06T18:36:23Z

Hwang at 18:23, 6 February 2023

2023-02-06T18:23:08Z

Hwang at 18:22, 6 February 2023

2023-02-06T18:22:41Z

Hwang at 18:20, 6 February 2023

2023-02-06T18:20:41Z

@@ Line 14: / Line 14: @@
 *Furthermore,&nbsp; the radio interface is responsible for other functionalities such as the&nbsp; "radio subsystem link control".
-[[File:EN_Bei_T_3_2_S1_v2.png|right|frame|Compilation of the logical channels of GSM '''KORREKTUR: full rate, half rate''']]
+[[File:EN_Bei_T_3_2_S1_v4.png|right|frame|Compilation of the logical channels of GSM]]
 Let's start with the&nbsp; &raquo;'''logical channels'''&laquo;.&nbsp; These can occupy either an entire physical channel or only a portion of a physical channel and fall into two categories:
@@ Line 99: / Line 99: @@
 ==The different burst types in GSM==
 <br>
-[[File:EN_Bei_T_3_2_S4_v3.png|right|frame|The different burst types with GSM '''KORREKTUR: logisch''']]
+[[File:EN_Bei_T_3_2_S4_v5.png|right|frame|The different burst types with GSM]]
 As just shown,&nbsp; a&nbsp; &raquo;'''burst'''&laquo;&nbsp; contains&nbsp; $156.25$&nbsp; bits each and has duration&nbsp;
 :$$T_{\rm burst} = T_{\rm Z} ≈ 577 \rm &micro; s.$$

@@ Line 115: / Line 115: @@
 #Access Burst&nbsp; $\rm (AB)$.<br>
 <br clear=all>
-'''(1)''' &nbsp; The&nbsp; &raquo;'''Normal Burst'''&laquo;&nbsp; is used to transmit data from traffic and signaling channels.&nbsp; The error protection encoded user data&nbsp; $($blue,&nbsp; two times&nbsp; $57$&nbsp; bits$)$&nbsp; together with three tail bits each&nbsp; $($red,&nbsp; during this time the transmit '''KORREKTUR: transmitted?''' power is regulated$)$,&nbsp; two signaling bits&nbsp; $($green) and&nbsp; $26$&nbsp; bits for the training sequence&nbsp; $($yellow,&nbsp; required for channel estimation and synchronization$)$&nbsp; result in a total of&nbsp; $148$&nbsp; bits.&nbsp; Added to this is the Guard Period of&nbsp; $8.25$ bits&nbsp; $($gray$)$.
+'''(1)''' &nbsp; The&nbsp; &raquo;'''Normal Burst'''&laquo;&nbsp; is used to transmit data from traffic and signaling channels.&nbsp; The error protection encoded user data&nbsp; $($blue,&nbsp; two times&nbsp; $57$&nbsp; bits$)$&nbsp; together with three tail bits each&nbsp; $($red,&nbsp; during this time the  transmitted power is regulated$)$,&nbsp; two signaling bits&nbsp; $($green) and&nbsp; $26$&nbsp; bits for the training sequence&nbsp; $($yellow,&nbsp; required for channel estimation and synchronization$)$&nbsp; result in a total of&nbsp; $148$&nbsp; bits.&nbsp; Added to this is the Guard Period of&nbsp; $8.25$ bits&nbsp; $($gray$)$.
 The two&nbsp; $($green$)$&nbsp; signaling bits &ndash; also called&nbsp; "stealing flags"&nbsp; &ndash;&nbsp; indicate whether the burst transports only user data or high-priority signaling information,&nbsp; which is always to be transmitted without delay.&nbsp; The&nbsp; "training sequence"&nbsp; is used to estimate the channel,&nbsp; which is a prerequisite for applying an equalizer to reduce intersymbol interference.
@@ Line 329: / Line 329: @@
 Another function of the radio interface is the control of the radio link.&nbsp; Thus,&nbsp; the so-called&nbsp; "Radio Subsystem Link Control"&nbsp; performs the following tasks:
 #It is responsible for the measurement of the reception quality. During an established traffic or signaling connection, the channel measurement of the mobile station is performed at regular intervals with regard to received field strength and bit error rate &nbsp; ⇒ &nbsp; &raquo;'''Quality Monitoring'''&laquo;. These values are transmitted in a measurement report to the base station via the signaling channel SACCH and used by it for power control and handover.<br><br>
-#The&nbsp; "Power Control"&nbsp; is necessary to ensure that all mobile stations only radiate with the minimum required power.&nbsp; The transmit '''KORREKTUR: transmitted''' power can be adaptively controlled in steps of&nbsp; $2 \ \rm dBm$&nbsp; between&nbsp; $43 \ \rm dBm$&nbsp; $\text{(level 0:}$&nbsp; $20\ \rm W)$&nbsp; and&nbsp; $13 \ \rm dBm$&nbsp; $\text{(level 15:}$&nbsp; $20\ \rm mW)$.<br><br>
+#The&nbsp; "Power Control"&nbsp; is necessary to ensure that all mobile stations only radiate with the minimum required power.&nbsp; The transmitted power can be adaptively controlled in steps of&nbsp; $2 \ \rm dBm$&nbsp; between&nbsp; $43 \ \rm dBm$&nbsp; $\text{(level 0:}$&nbsp; $20\ \rm W)$&nbsp; and&nbsp; $13 \ \rm dBm$&nbsp; $\text{(level 15:}$&nbsp; $20\ \rm mW)$.<br><br>
-#Base station transmit '''KORREKTUR: transmitted''' power is also adjusted in steps of&nbsp; $2 \rm dBm$&nbsp; to achieve optimum network capacity.&nbsp; An exception is the BCCH carrier with constant transmit '''KORREKTUR: transmitted''' power to allow mobile stations to make comparative measurements of neighboring BCCH carriers.<br><br>
+#Base station transmitted power is also adjusted in steps of&nbsp; $2 \rm dBm$&nbsp; to achieve optimum network capacity.&nbsp; An exception is the BCCH carrier with constant transmitted power to allow mobile stations to make comparative measurements of neighboring BCCH carriers.<br><br>
 #The&nbsp; &raquo;'''Adaptive Frame Alignment'''&laquo;&nbsp; &ndash; i.e. adaptive frame synchronization &ndash; is used to avoid collisions between uplink and downlink data to be transmitted or received by the mobile station offset by three time slots.<br>

@@ Line 335: / Line 335: @@
 [[File:EN_Bei_T_3_2_S11.png|right|frame|Adaptive Frame Alignment]]
 <br>
-This is shown in the adjacent graph.&nbsp; The downlink is represented in the middle area with a yellow background,&nbsp; where the data arrives at the mobile station&nbsp; $\rm (MS)$&nbsp; by the time&nbsp; $T_{\rm R}$&nbsp; $($"Round Trip Delay Time",by the time&nbsp; $T_{\rm R}$&nbsp; $($"Round Trip Delay Time",&nbsp; green marking$)$&nbsp;later than it was sent by the&nbsp; base transceiver station&nbsp; $\rm (BTS)$.
+This is shown in the adjacent graph.&nbsp; The downlink is represented in the middle area with a yellow background,&nbsp; where the data arrives at the mobile station&nbsp; $\rm (MS)$&nbsp; by the time&nbsp; $T_{\rm R}$&nbsp; $($"Round Trip Delay Time", by the time&nbsp; $T_{\rm R}$&nbsp; $($"Round Trip Delay Time",&nbsp; green marking$)$&nbsp;later than it was sent by the&nbsp; base transceiver station&nbsp; $\rm (BTS)$.
 In the upper area,&nbsp; the uplink is shown without&nbsp; "Timing Advance".

@@ Line 330: / Line 330: @@
 #It is responsible for the measurement of the reception quality. During an established traffic or signaling connection, the channel measurement of the mobile station is performed at regular intervals with regard to received field strength and bit error rate &nbsp; ⇒ &nbsp; &raquo;'''Quality Monitoring'''&laquo;. These values are transmitted in a measurement report to the base station via the signaling channel SACCH and used by it for power control and handover.<br><br>
 #The&nbsp; "Power Control"&nbsp; is necessary to ensure that all mobile stations only radiate with the minimum required power.&nbsp; The transmit '''KORREKTUR: transmitted''' power can be adaptively controlled in steps of&nbsp; $2 \ \rm dBm$&nbsp; between&nbsp; $43 \ \rm dBm$&nbsp; $\text{(level 0:}$&nbsp; $20\ \rm W)$&nbsp; and&nbsp; $13 \ \rm dBm$&nbsp; $\text{(level 15:}$&nbsp; $20\ \rm mW)$.<br><br>
-#Base station transmit power is also adjusted in steps of&nbsp; $2 \rm dBm$&nbsp; to achieve optimum network capacity.&nbsp; An exception is the BCCH carrier with constant transmit power to allow mobile stations to make comparative measurements of neighboring BCCH carriers.<br><br>
+#Base station transmit '''KORREKTUR: transmitted''' power is also adjusted in steps of&nbsp; $2 \rm dBm$&nbsp; to achieve optimum network capacity.&nbsp; An exception is the BCCH carrier with constant transmit '''KORREKTUR: transmitted''' power to allow mobile stations to make comparative measurements of neighboring BCCH carriers.<br><br>
 #The&nbsp; &raquo;'''Adaptive Frame Alignment'''&laquo;&nbsp; &ndash; i.e. adaptive frame synchronization &ndash; is used to avoid collisions between uplink and downlink data to be transmitted or received by the mobile station offset by three time slots.<br>

@@ Line 329: / Line 329: @@
 Another function of the radio interface is the control of the radio link.&nbsp; Thus,&nbsp; the so-called&nbsp; "Radio Subsystem Link Control"&nbsp; performs the following tasks:
 #It is responsible for the measurement of the reception quality. During an established traffic or signaling connection, the channel measurement of the mobile station is performed at regular intervals with regard to received field strength and bit error rate &nbsp; ⇒ &nbsp; &raquo;'''Quality Monitoring'''&laquo;. These values are transmitted in a measurement report to the base station via the signaling channel SACCH and used by it for power control and handover.<br><br>
-#The&nbsp; "Power Control"&nbsp; is necessary to ensure that all mobile stations only radiate with the minimum required power.&nbsp; The transmit power can be adaptively controlled in steps of&nbsp; $2 \ \rm dBm$&nbsp; between&nbsp; $43 \ \rm dBm$&nbsp; $\text{(level 0:}$&nbsp; $20\ \rm W)$&nbsp; and&nbsp; $13 \ \rm dBm$&nbsp; $\text{(level 15:}$&nbsp; $20\ \rm mW)$.<br><br>
+#The&nbsp; "Power Control"&nbsp; is necessary to ensure that all mobile stations only radiate with the minimum required power.&nbsp; The transmit '''KORREKTUR: transmitted''' power can be adaptively controlled in steps of&nbsp; $2 \ \rm dBm$&nbsp; between&nbsp; $43 \ \rm dBm$&nbsp; $\text{(level 0:}$&nbsp; $20\ \rm W)$&nbsp; and&nbsp; $13 \ \rm dBm$&nbsp; $\text{(level 15:}$&nbsp; $20\ \rm mW)$.<br><br>
 #Base station transmit power is also adjusted in steps of&nbsp; $2 \rm dBm$&nbsp; to achieve optimum network capacity.&nbsp; An exception is the BCCH carrier with constant transmit power to allow mobile stations to make comparative measurements of neighboring BCCH carriers.<br><br>
 #The&nbsp; &raquo;'''Adaptive Frame Alignment'''&laquo;&nbsp; &ndash; i.e. adaptive frame synchronization &ndash; is used to avoid collisions between uplink and downlink data to be transmitted or received by the mobile station offset by three time slots.<br>

@@ Line 310: / Line 310: @@
 Furthermore,&nbsp; it should be noted:
-*Binary FSK &ndash; even with continuous phase matching &ndash; generally represents a nonlinear modulation process.&ndash; Therefore,&ndash; coherent demodulation is actually not possible.
+*Binary FSK &ndash; even with continuous phase matching &ndash; generally represents a nonlinear modulation process.&nbsp; Therefore,&nbsp; coherent demodulation is actually not possible.
 *An exception is the MSK as a special case for the modulation index&nbsp; $h = 0.5$,&nbsp; which can be realized linearly as&nbsp; "Offset-QPSK"&nbsp; and thus can also be demodulated coherently.

@@ Line 287: / Line 287: @@
 [[File:EN_Bei_T_3_2_S10.png|right|frame|Power-spectral densities of QPSK and MSK]]
-&rArr; &nbsp; The left graph shows the log power-spectral density&nbsp; $10 \cdot \text{lg} \ {\it Φ}_s(f)/{\it Φ}_0$&nbsp; of&nbsp; "Minimum Shift Keying"&nbsp; $\rm (MSK)$&nbsp; compared to&nbsp; "Quaternary Phase Shift Keying"&nbsp; $\rm (QPSK)$,&nbsp; where&nbsp; ${\it Φ}_0$&nbsp; was&nbsp; "suitable"&nbsp; chosen.
+&rArr; &nbsp; The left graph shows the log power-spectral density&nbsp; $10 \cdot \text{lg} \ {\it Φ}_s(f)/{\it Φ}_0$&nbsp; of&nbsp; "Minimum Shift Keying"&nbsp; $\rm (MSK)$&nbsp; compared to&nbsp; "Quaternary Phase Shift Keying"&nbsp; $\rm (QPSK)$,&nbsp; where&nbsp; ${\it Φ}_0$&nbsp; was chosen&nbsp; "suitable".&nbsp;
 On the abscissa is plotted the normalized frequency&nbsp; $f \cdot T_{\rm B}$.&nbsp; For MSK,&nbsp; the bit duration&nbsp; $T_{\rm B}$&nbsp; is equal to the symbol duration&nbsp; $T$,&nbsp; while for QPSK holds:&nbsp; $T_{\rm B} = T/2$.

@@ Line 83: / Line 83: @@
 *Each cell is assigned some frequencies per&nbsp; "cell allocation"&nbsp; $\rm (CA)$.&nbsp; In adjacent cells one uses different frequencies.
-*A subset of the CAs is reserved for logical channels.&nbsp; The remaining channels are allocated to a mobile station as&nbsp; "mobile allocation''&nbsp; $\rm (MA)$.
+*A subset of the CAs is reserved for logical channels.&nbsp; The remaining channels are allocated to a mobile station as&nbsp; "mobile allocation"&nbsp; $\rm (MA)$.
 *This is used,&nbsp; for example,&nbsp; for&nbsp; "frequency hopping",&nbsp; where the data is sent over different frequency channels.&nbsp; This makes the transmission more stable against channel fluctuations.&nbsp; In most cases,&nbsp; frequency hopping is performed in packets.

@@ Line 134: / Line 134: @@
 *the&nbsp; &raquo;'''mapping in frequency'''&laquo;,&nbsp; based on&nbsp;
 #"cell allocation"&nbsp; $\rm (CA)$,
-#"mobile allocation''&nbsp; $\rm (MA)$",
+#"mobile allocation"&nbsp; $\rm (MA)$,
 #the&nbsp; "TDMA frame number"&nbsp; $\rm (FN)$,&nbsp; and
 #the rules for the $($optional$)$&nbsp; "frequency hopping";